740
T H E -JOL'RA'AL OF I A ' D U S T R I A L A N D E L V G I S E E R I ~ V GCHE-WISTRY
method, as the formeris the commercial method, and the only one used for extracting edible oils. For extracting the oil a cylindrical press was constructed by using an iron cylinder with an inside diameter of 31/4 inches and a height of 7 inches into which was fitted a closefitting piston. The cylinder was set on an iron plate perforated with several l/8 inch holes, and holes were drilled in the cylinder near the lower end t o facilitate the running out of the oil. When hydraulic pressure was applied t o the piston the oil exuded from the holes and collected in a metal pan in which the press had been placed. A pressure of 150 to 300 atmospheres was applied t o the piston. A second pressure was applied t o the material after breaking up the press cake and heating the press and the press cake to 5-60' C. The following table shows the yield of oil from the various samples, the total per cent of oil present, and the actual per cent of oil extracted: Total per cent of oil present
Per cent of oil present extracted
26.5
59.5
.........
......
..
7.5
70.2
..
42.7 23.2
.. ..
.. ..
The oils, as a t first obtained, were cloudy, and the hot-pressed were darker than the cold-pressed. After filtration through filter paper the oils became bright and clear, and were of the appearance and consistency of Italian olive oil. They possessed an agreeable hickory nut odor and flavor. The following table gives the constants as obtained from both these oils and for comparison those obtained a t the Alaine Experiment Station.' TABLE111-COXSTANTS
OF
HICKORY NUT OILS
C. amara
Specific gravity a t 24" C . . . . . . . . . . . . . . . . . 1,4699 Refractive index a t 20' C . . Hehner number., . . . . . . . . . . . . . . . . . 9 5 . 6 Reichert-Meissl number.. . . . . . . . . . . 0.48 Iodine value.. .................... 105.2 Saponification value.. . . . . . . . . . . . . . 190.0
........
C. oaata 0.9119 1.4699 95.7 0.47 106.8 189.6
Maine Expt. S t a . 0.9164 1.4696
......
...... 102.8
......
The similarity of the two oils is very evident. Perhaps the most important factor for comparison of the different classes of oils is the iodine value, for this is a measure of the unsaturated glycerides present, and thus determines whether the oil is drying, semi-drying or non-drying. The iodine value here obtained for hickory nut oil seems to classify it with the semidrying oils. Here belong cottonseed oil, corn oil, rape seed oil, Brazil nut oil, and beech nut oil. In the Of 'Onstants Of is shown a hickory nut oil with those O f cottonseed oil and those of the non-drying oil, "dz., olive oil. These figures show that hickory nut Oil very closely cottonseed oil, and would be difficult t o distinguish from it. The hickory nut oil is very agreeable as a salad oil, 1
LOCc i t
TABLBI V Hickory nut oil
Cottonseed oil Olive oil Specific gravity.. 0.9119 a t 24' C. 0.9203 a t 19' C. 0.9100 a t 24O C. Refractive index. 1.4699 a t 20' C. 1.4748 a t 15" C. 1.4670 a t 20° C. Iodine value.. 106.0 106.0 82.0 Saponification value.. . . . . . 190.0 192.0 190.0 ReichertMeissl number ......... 0.48 ...... 0.6 Hehner number.. . . . . . . . 9 5 . 7 95.6 95.4
.......
........
so that if it can be obtained a t a sufficiently low cost, it can be used for this purpose. The C. amara or t h e C. porcine (pig nut), which are now considered as absolutely of no value, would yield a t least a gallon and a half of oil per bushel and the nuts need only be crushed before they are pressed. SUMMARY
TABLEI1
Kind of sample Yield in per cent C. Ouafa-Whole. cracked, coldpressed.. 15.8 Hot-pressed, . . . . . . . 2 . 0 C. Ouata-Meats alone coldpressed.. ......... 30.6(a) Hot-pressed.. . . . . . . 17.5 C. Amara-Whole. cracked, coldDressed. . . . . . . . . . 22.1 Hot-pressed.. 3.8 (a) Only 100 atmospheres pressure.
Val. 5 , No. 9
I. The food value of hickory nuts is high. 11. The oils from the two species of hickory nuts, C. ovata and C. a m a r a , are practically identical and are similar t o cottonseed oil. 111. The oil retains the flavor of the hickory nut, and is practically equal t o olive oil. IV. The possibility of extracting the oil on a commercial basis should be further investigated. CHEMICAL LABORATORIES UNIVERSITY OF KANSAS LAWRENCE
THE ANALYSIS OF MAPLE PRODUCTS I A N ELECTRICAL CONDUCTIVITY TEST FOR PURITY OF MAPLE SYRUP' B y J . F. SNELL
The most commonly used adulterant of maple sugar is granulated sugar, which is, of course, chemically identical with the predominating constituent of the pure material. For the detection of such adulteration we are dependent upon measurements of the small quantities of the non-sugar constituents, the percentages of which in the syrup are necessarily decreased by the addition of the practically pure sucrose, together with the proportional quantity of water necessary t o convert it into a syrup. The ash, the soluble and insoluble ash, the alkalinities of these, the malic acid value, and the amounts of precipitate produced by lead subacetate and by normal lead acetate are alike lowered by such adulteration, though not necessarily in proportion to the amount of adulteration.2 Sucrose being a non-conductor of electricity, and the salt constituents conductors, it is reasonable t o 1 This test was described a t the Wzxshington meeting of the American Chemical Society in December, 1911, but publication was deferred until further experiments could be made, particularly (1) upon the effect of adulteration on the conductivity value and ( 2 ) upon the relation between the conductivity of the syrup and t h a t of its ash solution. This later experimental work has been carried out under my direction by hfr. J. h i . Scott, to whom my thanks are due for very competent assistance. This assistance was rendered possible by the Dominion Government Grant for the Advancement of Agriculture. Through the courtesy of Prof. Frank T. S h u t t , M A , F.R.S.C., 'the present paper was read before the Royal Society of Canada a t Ottawa, May 28, 1913. 2 The effect of such adulteration uDon the various anaiyticat values will be discussed in a later paper.
Sept., 1913
T H E J O C R N A L 0 F . I N D U S T R I A L A.YD ESGII\-EERISG
anticipate t h a t maple syrups adulterated with granulated sugar in more than very small quantities will show materially lower conductivities than pure maple syrups. Since with suitable apparatus a measurement of electrical conductivity can be made in a few seconds, a method based upon such a measurement would have a decided advantage in point of rapidity over any of the methods now in vogue.1 The most rapid methods hitherto proposed have depended upon precipitation with lead subacetate and measurement of the volume of the centrifugally-settled precipitate.' h-o great delicacy has been claimed for these methods, and even they require more time than a conductivity measurement. THE
CONDUCTIVITIES O F UNDILUTED P U R E SYRUP
Measurements of the conductivities of the undiluted syrup have been made upon 43 samples, all of Canadian origin. Eleven pairs of early and late products from the same or adjoining woods were sent me by the makers from various parts of the Province of Quebec in the season of 1911. Thirteen samples from Ontario and six from Quebec, all of the season of 1911,were kindly forwarded by Dr. Anthony McGill, Chief Analyst of the Inland Revenue Department, Ottawa, as fairly representative of the 450 odd samples collected by the Department for the purpose of establishing a standard of purity for maple syrup. Each of these was accompanied by a declaration of genuineness signed b y the maker.3 The remaining two samples of the 43 were made from identical.sap, one by rapid boiling in a modern evaporator having a corrugated pan, the other in an iron kettle, not entirely free from rust, with very slow boiling. TABLE I-SUMMARY OF DENSITIESA N D COKDUCTIVITIES O F 42 GESUINE CAXADIAK MAPLE SYRUPS Conductivity Sp. gr. K X 105 15' C. 2 5 " C. Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.333 18 7 Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.305 9.6 Maximum ......................... 1.355 33.f, Percentage deviation of minimum from mean.. . . -2.1 -49 Percentage deviation of maximum from m e a n . . . 80 1. 6
+
+
A summary of the variations of the specific gravity and of the electrical conductivity of 42 of these 43 syrups is given in Table I. The syrup omitted from this summary is one of the Inland Revenue Department samples, which was of extremely low density. Its specific gravity was I . 279, its moisture content (according t o the analysis made in the Inland Revenue As long ago as 1889, E. Reichert, Zezt. anal. Chem., 28, 14 (1899), and more recently, Hugh Main, International Sugar Journal, 11, 334 (1909); Zeit. Ver. Zuckerind, 59, 7x3 (1909); Chem. Abstr., 3 , 2249 (1909) and A. E Lange, Z . V e r . Zuckerind., 60, 359: Chem. Abstr., 4, 1554 (1910) have proposed methods of estimating t h e ash of sugars and syrups from their electrical conductivities. These methods appear t o have given good results in t h e hands of their authors b u t have been adversely criticized b y o t h e r s Reichert's, b y Fock and Plath, Zeit. Ver. Zuckerind., 39, 710 (1889); Main's a n d Lange's, b y A. Trenkler, Oesferr-und Zeit. Zuckerind.. 39, 437; Chem. Abstr., 4, 308 (1910). Hortvet, J . A m . Chem. SOC..26. 1543 (1904); Bureau of Chem., U. S. Dept. Agr., Bulletin 107, 72; Jones, Vermont Agr. E x p t . Sta., 18th Annual
Report, 1906, 322. See Bulletin 228 of the Laboratory of t h e Inland Revenue Department (1911). The syrups examined were Nos. 184-191, 278, 281 a n d 284 of this bulletin.
193-195, 211-214, 263.
CHEMISTRY
741
Laboratory) 38,j g per cent, and its conductivity ( K X 1 0 5 ) 45 . o . As a general rule, the syrups of high density showed low conductivities and those of low density showed high conductivities. This indicates that in undiluted syrups the concentration of the sugar has more influence upon the conductivity than has the concentration of the electrolyte components. The syrup made in the iron kettle had a specific gravity of 1.326,and a conductivity of 25.9, while that made from the same sap by rapid, shallow boiling in a n evaporator showed a specific gravity of 1.334,and a conductivity of 22.4. This is in harmony with the general rule of lower conductivity accompanying greater density. The minimum conductivity (9.6) was shown by the syrup of maximum density ( I . 355),while the maximum conductivity (33.6) was found in a syrup of density I . 31 I. THE
EFFECT OF DILUTION
The results of the above measurements indicate t h a t a s the water-content of maple syrup increases, the conductivity increases. I n other words, the more dilute the solution the greater the conductivity. This is not in line with the usual behavior of aqueous solutions of electrolytes. I n general, the specific conductivity of such solutions decreases with dilution. The thought, therefore, suggested itself t h a t if one continued t o dilute maple syrup with water, a point of dilution must eventually be reached a t which the conductivity would cease t o increase and begin to decrease-a point of maximum conductivity. This proved t o be the case, the maximum occurring a t a dilution of one volume of syrup to two of water, i. e., in a mixture containing 331/3 per cent of syrup by volume, or 39.6 per cent of syrup of normal density (I, 3 2 0 ) by weight. TABLE11-EFFECT OF DILUTIONUPON CONDUCTIVITYOF SYRUP
s3,rug I Per cent maple syrup P e r cent maple syrup b y volume by weight Conductivity value 5 10 20 25 30 331/3 40 50 GO 70 80 90 100
6 6 13 0 25.1 30.9 36 5 40 1 47.2 57.3 66.8 75,s 81.3 92.3 100.0
62 100 147 163 171 175 169 153 123 99 63 44 32
Syrup I1 Per cent maple syrup by weight 20 30 39.9 40 GO
83 l/a 100
Conductivity value 127 141 148 147 127 69 26
Table I1 and Diagrams I and I1 give results typical of the effect of dilution upon the specific conductivities of maple syrups.
THE JOCRiY.4L OF 1-YDUSTRIAL AZ;D E4YGI-I\'EERI.YG CHE3IISTRY
742
1
IO
50
?O .
50
+O
CO
90
P I
70
100
PEP CENT MAPLE 5 t ' R V P D1.4GRAM
Vol.
j,
No. 9
The range of variation of the conductivity of pure maple syrups thus diluted with two volumes of water is much narrower than that of the conductivity of the undiluted syrups. The mean conductivity a t 2 j o C. ( K X 1 0 5 ) of the diluted solutions of the 42 syrups of Table I was I j3, or over 8 times the mean conductivity of the same syrups in the undiluted state. The minimum was 1 2 0 , the maximum 203, the latter being the conductivity value of the syrup made in the iron kettle. The minimum deviates from the mean by z I per cent, as against 49 per cent in the undiluted syrup; the maximum by 33 per cent, as against 80 per cent for the undiluted syrup. We have thus a total range of j 4 per cent for the diluted as against 1 2 9 per cent for the undiluted syrup. The fortythird syrup, omitted from the summary in Table I , on account of its extremely low density and high conductivity, gave a perfectly normal conductivity value (167) when diluted with two volumes of water. The maximum conductivity, or more strictly speaking, the conductivity of the mixture of one volume of syrup with two volumes of water is, accordingly, made the basis of the method here proposed. METHOD
I
On each side of the point of maximum conductivity there is a considerable range of concentrations, within which the conductivity differs very little from the maximum. This renders i t possible t o measure the maximum conductivity of diluted maple syrup without observing much precision in making up the mixture of maple syrup and water. This is a point of great practical advantage in relation to the rapidity of the method described below. I t is not necessary to weigh the syrup nor t o reduce i t to a definite density.
Measure out into a small beaker (or directly into the conductivity cell) a suitable quantity ( I j cc.) of the syrup, allowing thorough draining. Using the same graduate, add t w o successive portions of water, each equal in volume to the syrup taken. Mix thoroughly, pour into conductivity cell, bring t o z j o C . , and make the measurement. Divide the constant of the cell by the observed number of ohms and multiply the result by I O O , O O O . Genuine syrups have given values of I I O t o 2 0 0 , but further experience may extend these limits a little.' Syrups giving conductivity values distinctly outside these limits may be condemned. Those giving normal values are not necessarily pure and should be further examined by well-established tests. APPARATUS
101 to
I
IO
20
,o
+a
so
PER C E N T
'0
MAPLE
TO
80
90
,M
SIRUP
DIAGRAM I1
An ordinary z j cc. graduate can be used to measure the dyrup, the two portions of water subsequently measured from the same graduate serving t o rinse out the syrup which adheres to the sides.
The essential features of the apparatus are: I . A low voltage electrical current operating a n induction coil. 2. A conductivity cell of a form suitable for liquids of low conductivity, and with electrodes not easily displaced. 3. A Wheatstone bridge m-ith telephone. 4. A device for exact regulation of temperature. I n the present work a Kohlrausch Universal Bridge bearing the name plate of Messrs. Philip Harris & Co., Birmingham, England; has been used. The induction coil with which this bridge is fitted was operated by two lead accumulators connected in series. A small Deveau telephone was found t o give better results than a Bell. With this very convenient bridge and telephone there was no difficulty in obtaining a sharp minimum of sound. The conductivity cell used a t first was of the form represented in Fig. 2 9 5 (p. 4 0 2 ) 1 I have collected nearly 130 syrups of the season of 1913, direct from the sugar bushes of Ontario and Quebec a n d intend determining the limits of conductivity value in these both a t 25' and a t 20' C. Xo. 7072 in this firm's Physics catalogue, Vol. 1.
Sept., 1913
T H E JOGR-YAL OF I-VDCSTRI.4L A-\*D E.TGISEERI.YG
of Ostwald and Luther’s “Physiko-chemiker Nessungen,” 2nd edition (1902). Its capacity was about 5 0 cc. I t had electrodes of 2 . 5 cm. diameter set I cm. apart, which maintained their position satisfactorily,
CHE-IIISTRI-
743
Eimer & Amend, of New Tork. The platinum electrodes of this special cell are of B. & S. gauge No. 2 7 , and are 3 . 2 cm. in diameter. They are adjustable as t o distance, but are firmly held in position by set-
TABLE 111-SYRKPS ZIADE I N LABORATORY SEASON O F 1912 Dry h B D E G H matter ConConducC SolInsolI: Alkalinity Xlkal inity Insolfrom ductiritv tivitv Total ash uble ash uble ash Alkalinity SolDate Density de nsi t 1 7-alue 1-alue. ash Dry basis Drv b s i s D r y basis Total ash uble ash uble ash so. made saps 1 5 ‘ C. 0.45 0.51 1 15 0.73 n 95 n 44 I Apr. 6 H a r d and s o f t 1.329 66.5 150 0.50 1.42 0.33 n 92 61 0.99 0.66 Xpr. 7 H a r d a n d soft 1.329 2 66 5 164 0.46 0.50 1 46 I .no 5T 0 8s 0 3s Xpr. 10 Hard and soft 1.326 66.0 144 3 0.3s 1 42 0.46 0.86 n 95 0 57 4 Apr. 1 1 H a r d and soft 1.32T 66.2 153 56 5 Apr. 12 H a r d and soft, evaporated 0.83 1 30 0.47 1 .no 0.5s 0 42 on steam b a t h 1 333 67.1 145 61 6 .Ipr. 12 H a r d and soft, evaporated 1.19 0.46 0.5s 0 59 n 29 0.73 over flame 1.320 65.0 135 5S 1.30 n 4s 0 3.= 0 50 0.82 7 Apr. 13 H a r d and soft 1 ,325 65.8 50 0,55 133 1 11 0.45 n 52 0.39 0.66 s Apr. 1.5 H a r d a n d soft 1.325 I52 bS 0.91 65 S ... 1 41 0 43 0.98 0.85 ... 9 -1pr. 18 H a r d and soft 1.327 66.2 135 50 0 43 0.52 1.1s 0.36 0.82 65 . n 48 0.95 H a r d and s o f t 1 320 119 in Apr. 23 1, 31 0.47 0 50 0.45 n 84 66.5 126 54 0.98 H a r d and soft 1.329 11 Apr. 25 1 61 n 49 5s 1.09 0.46 0.63 1 12 I55 66 2 IIard and soft 1.327 12 -4pr. 29 0.46 1.32 0.50 0.45 0.36 .... 143 56 0.94 Average results f o r mixed saps. . . . . . . . . . . , . . 40.0 10 6 5,; 30.2 .... 14.7 15.9 32 0 21 .4 Percentage deviation maximum from mean . . . . . 35.6 15.9 21.7 23.3 .... 14 3 6.1 30 n 16,s Percentage deviation minimum from mean . . . . . 0 41 0.46 1.1; 0.41 0.76 13 .Ipr. 15 Hard 1.322 65 . 4 145 43 0,s; 0.51 1 .?9 0 46 0.83 0.49 152 57 1 on 14 Xpr. 16 Hard 1.327 66.2 Apr. 20 Hard, evaporated over 15 0 . 5 0 1.07 0.4i 0.55 1.39 0.39 146 65.4 flame 1.322 54 16 Apr. 20 H a r d , caramelized in 1.25 0.37 0.45 0.83 0.97 boiling 1.319 148 50 0.60 64.9 1.55 0.52 0.48 0.5; 1.03 1.05 17 Apr. 22 IIard 1 330 66.6 148 .. 0.45 0 . 5 1 0 . 4 7 0.93 1.45 Apr. 24 Hard 1.325 141 57 0.96 18 65 .3 0.56 0.42 0.81 123 52 0.3s 0.94 19 Apr. 2 4 Hard 1.325 65.8 137 0.46 0.9T n 47 0.50 0.88 1.34 .... 53 145 Average results for h a r d sap s y r u p s . . . . . . . 15.7 8.2 27.i 14 0 13 n 17.0 .... 4.5 T.O Percentage deviation maximum f r o m m e a n . . . . . . 19.1 26 n 10.9 13.6 12.7 10.3 Percentage deviation minimum from m e a n . . . . . . . .... 5.5 9.4 1.1s 0.40 0.4: 0 43 0 78 0.90 20 Apr. 16 Soft 1.321 65.2 134 54 0.42 0.39 1.10 0.44 0.66 21 Xpr. 20 Soft 1.322 55 0.31 135 65.4 0.54 n 3s 1 27 0 55 0.72 .. 0.92 143 22 Apr. 22 Soft 1.330 66,6 1.13 0.46 56 0.ss n 4s 0 40 0,72 1.59 .... Average results for s o f t sap syrups.. . . . . . . . 4.4 12.5 7,s 7.5 19 6 5 3 .... 6.5 3 6 Percentage deviation maximum from m e a n . 13 n s .n 5 0 6.5 3.3 12.5 .... 3.6 3.6 Percentage deviation minimum from m e a n . .
.
.
General average.. . . . . . . . . . . . . . . . . . . . , . . Zlaximum . . . . . . . . . . . . . . . . . . . . . . . . . . . Minimum. , . . , . . . . . , . . . . . . . . . . . . . . . . . . . Percentage deviation m a x i m u m from m e a n . Percentage deviation minimum from m e a n . ,
. ~. . .
..
.. ..... .. . . .
TABLEIV-FULL
h Number
Run
1
Early Early Early Early Early Early Earls Early Late Late Late Late
2 3 4
5 6
8 9 10 11 12
Conductivity value
133 149 152 139 I47
145 139 162 157 149 13s 155
....
.iNALYTICAL
143 164 119 14.6 16.5
55 6s 43 23.6 12.7
0.49 0 66 0.35 30.6 23 6
0.46 0.63 0.29
3T.0 3; 0
1.31 1.61 1 .in 22.9 16 0
0.46
0.85
0.55
1.12 0.66 31.8 22.4
0.36 19.6 21.7
DATA FOR TWELVES>7RUPS O F TABLE1
C D E Total ash Soluble ash Insoluble ash Dry basis Dry basis Dry basis 0.30 0.46 0.34 0.~2 0.59 0.23 0 59 0.61 0.25 0.86 0.61 0.25 0.78 0.50 0.2s 0 89 0 5s 0.31 1 .n9 0 61 0.45 1.14 0.79 0.35 1.35 (1.93 0.45 0 86 0.57 0.29 0.39 0.60 0.20 1.14 0.62 0.57
Average. . . . . . . . , . . , . . . . . . . . . . . . . . 15 0 n 96 0.62 Per cent deviation of maximum from mean.. , . . . . . . . . . . . . . . . . . , , , , 24 7 43 s 50 n Per cent deviation of minimum f r o m mean . . . . . . . . . . . . . ... .. 11 .3 1s.s 25.8 (u) Determined upon 25 g. dry m a t t e r instead of upon 25 g. syrup.
0.94 1 .09 0.s1 16.0 13.5
0.34 52.9
F .klkalinity Total ash
1 .n+ 1 ni 1 05 0.93 0.89 I 08
1 03 1.20 1.63 1.12 1.01 1 14 1.10
4s 2
G H .alkalinity Alkalinity Canadian Soluble ash Insoluble ash Lead No. 0.46 0.58 3.36 0.43 3.10 0 5S 0.52 2.95 0.5; 0 4s 0.45 2.82 2.93 0.45 0.44 0.56 0.52 3.30 0.51 0.52 2.64 0.64 0.56 3.39 0.91 0.i2 3.29 0.56 3.44 0 56 n 50 0.51 2.i n 0 54 0.60 3.62
0 56 62 5
0.5; 35 .5
3 13 15 6
Modified Winton Lead No. ( a )
1.74 2.11 2.04 1.35 1.96 2.15 1.56 2.33 2 .n4 2.40
,
2.10
1 .85
2 02 13.8
32.4 19.1 li.9 18.9 15 .6 22.5 Bull. 228, Laboratory of the Canadian Inland Revenue Department.
as-was demonstrated by repeated determinations of the cell constant. Later, a special cell of the same type mith extra heavy electrodes and with a thermometer set in the cover was made for me by Messrs.
screws. The thermometer range is 2 0 ’ to 3 0 ° , graduated in tenths. This type of cell has proved perfectly satisfactory for the purpose. I n routine n-ork it might be advisable t o have a
744
T H E J O U R l Y A L OF IlVD U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
considerable number of cells fitting the same pair of electrodes. These could be filled with the different samples and set in a thermostat t o come to the required temperature, when measurements of all could be made in rapid succession. I have not used a thermostat in this work, but have regulated the temperature by placing the conductivity cell in a beaker of water of a suitable temperature, a fraction of a degree above or below that desired, and stirring the contents of the cell with the electrodes until the thermometer within the cell showed the correct reading. The cell constant was determined b y use of 0 .I , 0 . 0 2 and 0 . 0 1 M potassium chloride solution, made up a t 18' C. from the ignited C. P. salt, assuming for these' a t z s 0 C. the conductivities 1 2 8 9 , 2 7 6 . 8 and 1 4 1 . 2 X ,
219-220°
Vol. 5 , No.
Q
F., and filtered through double S. & S. No. Their densities a t 1 5 ' C. were then
597 filters.'
1 . 3 2 5 , 1 . 3 2 1 and 1 . 3 3 2 , respectively. Two of these Vermont syrups gave lower conductivity values than any of the Canadian syrups, viz., I I O and 1 1 5 . The third gave a value of I 2 2 . The ash values of these three syrups were also exceptionally low. Complete data for these syrups, as obtained by Professor Jones and myself, are given in Table V.
TABLEV-ANALYSES O R THREEVERMONT SYRUPSBY C. H. JONESA N D J . F. SNELL
No.
1
I o-6. R A N G E O F VARIATION O F THE CONDUCTIVITY VALUE I N
2
G F N U I N E SYRUPS
3
BY
Per cent AlkaAlkaPer cent Insoluble linity linity Conduc- Malic Total ash ash Soluble Insoluble tivity acid Analyst Dry basis Dry basis ash ash value value Jones Snell Jones Snell Jones Snell
0.70 0.71 0.68 0.83 0.64 0.70
0.37 0.59 0.33 0.32 0.25 0.23
0.35 0.37 0.39 0.42 0.36 0.37
0.45 0.44 0.44 0.50 0.35 0.38
,
.,
115
...
122
.. ,
0.44
,. 0.45
.. 0.39
110 .. I n addition t o the 4 3 syrups referred to above, the conductivity value has been determined on 2 2 syrups The minimum value yet found in a genuine syrup made in this laboratory in the season of 1 9 1 2 (see is 1 1 0 . The maximum of 2 0 3 obtained with the syrup Table 111). These syrups were all made from the sap prepared in the iron kettle has not been reached in of ten trees in the woods of the Macdonald College any other pure syrup. The highest value yet found farm-six hard and four soft maples. They repin a syrup actually prepared for the market is 1 9 7 . resent the runs of different days from April 6th to The limits of variation of genuine syrups may, thereApril 29th; some were made from the sap of the soft fore,' be tentatively set a t I I O to zoo. maples alone, others from the hard maples only, The mean conductivity of the 68 syrups may most though the majority represent the mixed sap of the fairly be estimated by giving the mean of the 2 2 ten trees. They were boiled down in basins on gas syrups.made from the trees on the Macdonald College stoves with the exception of one (No. s), which was farm a weight of 2-the same as one pair of early and evaporated on the steam bath. These 2 2 syrups late run syrups. We thus obtain for the 48 syrupsshow a range of 1 1 9 t o 164, average 1 4 3 . This is a 4 6 actual and 2 theoretical-a mean conductivity total range of 3 1 . 4 per cent. This is about the same value of 1 5 0 . This is approximately equal to the range of variation as is shown by the total ash, and a electrical conductivity of an 0 .o I M aqueous solution much lower range than those shown by the soluble of potassium cjloride ( 1 4 1 . 2 ) . ash, the insoluble ash and the alkalinities. Table I V includes analytical data for twelve of T H E R E L A T I O N O F THE C O N D U C T I V I T Y V A L U E T O T H E ASH DATA the Quebec syrups included in the summary given in Since the salt components of maple syrup are unTable I. These were examined to determine whether this apparent advantage of the conductivity method doubtedly responsible for the electrical conductivity, held for syrups of various origin, as well as for those relations between the conductivity value and the ash from a single bush. I t will be seen that among these data are worthy of investigation. From the investigations of Hortvet,' Jones3 and Bryan4 i t is clear t h a t 1 2 syrups the range of the conductivity value is much narrower than that of the total ash and narrower also maple syrup ash consists largely (viz.,to the extent than that of any of the other data except the Canadian of about 85 per cent) of the carbonates of calcium and potassium, the two metals being present in about lead number. If this narrowness of range shall be found to be chemically equivalent quantities. The three investicharacteristic of the conductivity values of pure gators are in close agreement as regards the lime conmaple syrups in general, i t will be a point of advantage tent which is in the neighborhood of 2 2 per cent. Bryan finds an average of 3 8 per cent of potash in for this method. I have also examined three syrups made a t the Ver- I O O syrups, Jones one of nearly 3 5 per cent in 6 syrups, mont Agricultural Experiment Station under the two of which were composites of a number of samsupervision of Prof. C. H. Jones, who advised me that ples, while Hortvet finds about 31 per cent in each of they were prepared with great care, every opportunity two syrup ashes. Hortvet alone has determined carbeing given for the malate of lime to settle out." These bonic acid. His results show an average of about syrups were exceptionally light in color. As received, 30 per cent in the two sample :. The proportions of they were of exceptionally high density, a s indicated these three constituents of the ash may accordingly by 'Prof. Jones' refractometer readings, viz., No. I a t be placed a t the following figures as a rough estimate: 2 4 . 7 5 ' C., 1 . 4 6 3 2 ; No. 2 a t 2 ; . 5 O C . , 1 . 4 6 5 1 ; No. 3 1 Jones, Vt. Agr. Expt. Sta., 18fh Amual Rebort. 1906, 328; d s m a t 2 4 . 7 5 ' C., 1 . 4 6 2 3 . For my own analyses they Bulletin 167, 470 (1912). a J . A n . Chem. Soc.. 26, 1541 (1904). were di uted. with water, boiled t o a boiling point of a vt. Agr. Expt. Sta.. 18th Annual Refiorf. 1906, 331. ('
1
Ostwald-Luther, Physico-chemische Messungen, 2nd edition, p. 407.
4
Bur. of Chem., U. S. Dept. Agr., Bullefin 184 (1910).
T H E J O G R S A L OF IATDL'STRIAL A;VD EI'1:GIA:EERIh'G CHE31ISTRY
Sept., 1913
P e r cent Molecules
.. KaO CaO . . . . . . . . . . . . . . . . , . . . .. . . . COz . . . . . . . . . . . . . . . . . . . . . . . . .
E;:1 ]
35 22 30
sum, 0.76
0.68
-
S u m , . . . . . . . . . . . . . . . . . . . , . . 87 These results indicate that organic salts of potassium and calcium are the chief electrolytes of thesyrup.' Potassium, having a higher ionic conductivity than calcium, may be expected to contribute a little more than a n equal share t o the conducting power of the
TABLEVI-RATIOS
g
i
Xumber l 2
1
.x I
=
(
in 11 12
Average mixed s a p . , . . , , . . . . . Per cent deviation of maximum from m e a n . , , . , . . . . . . . . . . . , Per cent deviation of minimum from mean. . . , . . . . . . . , . . . ...
.
4I vi
13 14
s ;;
El
19
Average hard m a p l e . . . , . . . . . . . . . Per cent deviation of maximum from m e a n . . . . . . . . . . . , . . , . . . . Per cent deviation of minimum from m e a n . . . . . . . . . . . . . , . .
O F THE -1SALSTIC.4L
B/B A/C Conduc- Conductivity tivity syrup+ syrup+ ConducTotal ash tivity ash
.. 2 52 2.53 2.73 2.38 2.33 2.76 2.24 2.70 2.48 2.33 2.67
158 166 164 161 145 153 162 167 153 125 129 142
341 248 379 268 250 229 394 292
2.52
152
Considered by themselves, the ratios of Table VI would indicate that the closer relationships are those between, on the one hand, conductivity and weight of the total ash and on the other hand conductivity and alkalinity of soluble ash. I t is t o be remembered, however, that these syrups were all from the one bush, and were manufactured on a small scale in the laboratory. As will be pointed out later, they are also peculiar in their ratios of the alkalinities of soluble and insoluble ash. Table VII, which refers to more representative
DATA FOR 22
A/D A/F ConducConductivity tivity syrup+ syrup+ Soluble .4lkalinitv ash total ash
277 252 337
127 115 99 108 112 113 106 137 96 101 96 96
297
in9
...
MADE IN LABORATORY (SEETABLE 111) A/G A/H B/D B/G ConducConducE/G Conduc- Conductivity Alkal. tivity tivity tivity ash+ total ash+ syrup+ syrup+ ash+ Alkal. Alkalinitv Alkalinitv Soluble -1lkalinitv sol. ash sol. ash sol. ash insol. ash ash SSRUPS
333 328 313 333 293 288 338 3 14 3 31 268 316
205 178 144 178 175 185 168 230 138 145 150 138
314
170
309
G/H Alkal. sol. a s h + Alkal. insol. ash
...
...
92
112 in8 126
122 124 122 129 126 104 151 116 133 115 118
2.62 2.84 3.17 3.09 2.77 2 .59 2.71 2.47 3.28 3.28 2.79 3.29
116
124
2.91
0 54
ijn
98 105 98 143 131
..
62 54 46 53 57 63 57 68 44 44 56
44
9.5
9.9
32.7
25.7
7.6
35.3
29.3
21.8
13.0
9 7
11 , I
17.8
22.9
11.9
14.6
18.8
20 7
16.1
15,l
29.2
354 310 311 247 30s 313 361
124 118 105 116 95 97 111
354 330 292 329 285 300 326
191 183 164 178 144 144 169
117 116 115 83
2.48 2.63
167 152 143 152 141 147 146
127 137
121 124
2 ,85 2.80 2.78 2.84 2.98 3.09 2.69
2.74
150
315
109
317
168
116
118
2.86
3.02 2.66 2.70 2.96
...
..
117 124 1os 111
...
54 55
56
54 50 48 52
53
10.2
11.3
14.6
13.8
11.7
13.7
18.1
5.1
8 .o
5 7
9.5
6.0
21.6
12.8
1n.i
14.3
25.4
5.9
5.9
9 4
2.48 2.33
....
149 167 161
285 321 274
114 123 117
335 307 269
172 205 206
Average soft maple.. . . . . . . . , , . Per cent deviation of maximum from m e a n . . , . , . . . . . . . . . . . . . . Per cent deviation of minimum from m e a n . . . . , . . . , . . . . , . . . . .
2.41
159
293
118
304
194
General average. . . . . . , . . . , . . . , . 31aximum. . . . . . . , . . . . . . . , , . . . , , 31 inimum. . , , . . , . . . . . . . , . , . . . Per cent deviation of maximum from m e a n . . . . . . . . . . . , . . , . . . . Per cent deviation of minimum from m e a n . . , . , , . . . , . . , . . .
2.58 3.02 2 24
2 9
5 .n3
9.6
4.2
3.3
6.3
6.5
3.4
1
i4
167 125
302 394 229
1i n 137 95
...
2.95 2.50 2.31
51 67 76
134
2.59
63
115 138
135 132
... 127
10.2
6.2
8.7
0.7
13.9
16 9
11.5
11.3
9 4
1.4
10.4
21.5
2.85 3.29 2.31
0 55 76 44
313 354 268
172 230 138
117 150 92
123 151 104
17.1
8 4
30.5
24.5
13.1
33.7
28.2
22.8
15.4
26 7
13.2
18.8
24.2
13.6
14.4
19.8
21.4
15.4
18.9
26 7
syrup. But its Preponderance is not such as to justify a confident prediction that the conductivity value will be more closely related to the soluble ash (consisting mainly of potassium carbonate) or its alkalinity than to the total ash or its alkalinity. I have, therefore, made calculations of the ratios of several of the data of Tables 111 arid IV and present these ratios in Tables VI and VII. 1
74 5
Magnesium a n d sodium salts are present in minor proportions.
samples, shows no material difference in the variability of the ratios of the conductivity value to the different ash data, If anything, the conductivity is more closely related to the total alkalinity than to the separate alkalinities of either the soluble or the ash. The range of variation of any of these ratios is somewhat wider than that of the ratios of the total alkalinity to the soluble alkalinity.
T H E J O r R S A L OF I S D C S T R I A L A N D ElYGIA\'EERI2\'G
746 TABLE VII-RATIOS
O F THE
A/C
F2
%;
6
>.
I.
ANALYTICAL DATAFOR T H E 12 QUEBEC SYRUPS OF TABLEIV A/H A/D A/E A/G a
.z n .e I
&> .*- .*B> 'Sc .*$3 * .y" a%a
'3 > U
3%
$ sg
B 6./. 0" .I.
V%
z
2.5
4
Y" m a q as'c E 4 d
CWi
5 .I.
C 4
6.I.
B
9.g .s3 U 6
2rc a 4 I 5 .I
1 2 3 4 5 6 7 8 9 10 11 12
166 182 171 162 188 163 128 142 136 173 155 139
289 253 249 228 294 250 228 205 20 1 262 230 255
128 148 145 149 165 134 135 135 115 133 137 138
289 25 7 287 290 327 259 273 253 205 266 276 293
229 347 292 309 334 279 267 289 2 60 266 27 1 263
Average.. . . . . , . . . . Per cent deviation of max. from mean Per cent deviation of min. from mean
159
245
139
273
284
18.2
18 .o
18.7
19.8
22.2
14.7
28.6
19.5
18 . O
17.2
24.9
19.4
11.7
24.8
2.26 1.74 1.98 1.94 1.98 1.93 2.02 1.88 1.79 2.00 2.02 2.11 197
79 135 102 107 102 108 98 114 126 100 98 90
CHEAMISTRY
As intimated above, the syrups upon which the determination of the conductivity of the ash was made are peculiar ip their low ratio of alkalinity of soluble t o that of insoluble ash. They average 0.54. On the 94 syrups examined by Jones, the average value of this ratio is 0.94; on the 13 upon which Hortvet made these determinations it is 0 . 8 5 ; Bryan's general average for 481 syrups is 0 . 7 7 , although for the T O O syrups selected by him for ash analysis, I find the average t o be 0.87; and the average for the 1 2 syrups of Tables IV and VI1 of the present paper is I . o s . I t is clear, therefore, that the syrups made in the laboratory (Tables I11 and VI) are of exceptional character. Under these conditions I do not feel justified in drawing any conclusions from the results obtained in the determination of the electrical conductivity of the ash solution. This property is, however, worthy of further study.
105
TABLEVIII-CONDUCTIVITY Number
CONDUCTIVITY VALUE O F THE ASH
Among the data of Tables I11 and VI is included for 19 syrups a figure designated "Conductivity Value of the Ash." This was determined according t o the following method: 5 grams of syrup are ashed in a platinum dish. The ash is boiled with 30 cc. water for two minutes, filtered through a 7 cm. filter and washed with hot water to a volume of nearly 50 cc. (the residue is ignited and weighed as the insoluble ash). The cooled filtrate is made up t o exactly 50 cc. and the conductivity measured a t 25' C. The solution is washed out of the conductivity cell and titrated for alkalinity of soluble ash. This method departs from the conventional one for determination of soluble and insoluble ash in maple products in using only 50 cc. of hot water on the ash of 5 grams of syrup, instead of roo cc. Possibly i t might be preferable t o adhere t o the conventional method of separating soluble and insoluble ash and t o make the determination of conductivity value of ash in a volume1 of I O O cc. instead of jo cc. To determine whether there is any material difference between the results obtained with the two different quantities of wash water, Mr. Scott has repeated the determinations upon syrups Nos. 2 , 5 and 1 1 , using I O O cc. of wash water. The results obtained by the two methods are compared below: Alkalinities as determined with use of 5 0 cc. wash water
100
cc. nash nater
7 -
syrup No. Date made 2 Apr. 7-9 5 Apr. 12 11 Apr. 25 Average,
Sol. ash 50 47 47
Insol. ash 92 83 84
Ratio 0.54 0.57 0.56 0.56
Sol. ash
Insol. ash
46 52 52
82 86 84
V O ~j, . NO. 9
Ratio 0.56 0.60 0.62 0.59
I infer from these results t h a t the difference between the two methods of washing is of little consequence. 1 I n the A. 0. A. C. provisional method for saccharine products in general, only 60 cc. of water are used. SBe Bur. of Chem.. Bullelin 107, 68 (1908). Hortvet followed this method.
1 2 3 SYRUPS
No. 1 diluted 4 5
KO,2 diluted 6 7 8 9 10 11
12 13 14
VALUES
Description Corn syrup Golden syrup Molasses
OF
NON-MAPLESYRUPS Specific Conductivity gravity value
DILUTEDTO DENSITYOF MAPLE Corn syrup Corn syrup Corn syrup Golden syrup Golden SYNP Golden syrup Molasses Molasses Molasses Molasses Cane sugar syrup from granulated sugar Cane sugar syrup from pale brown sugar Cane sugar syrup from pale brown sugar
1.40 1.44 , . .
2.51 414 65 6
SYRUP 1.339 1.320 1.320 1.320 1.320 1.320 1.320 1.320 1.320 1.320
253 359 209 427 392 403 1121 1280 604 1250
1.314
0.5
1.329
178
1.333
185
T H E C O K D U C T I V I T Y V A L U E S O F NON-MAPLE S Y R U P S
Table VI11 gives the conductivity values of a number of non-maple syrups. I t will be seen that syrup made from granulated sugar is practically a nonconductor, that syrups from partially refined cane sugar may give values within the limits found for pure maple syrups, and that all of the others give conductivity values distinctly above the limits for maple. I t is clear, therefore, that values either above or below the limits for genuine maple syrup may be produced by adulteration. Syrups yielding values either abnormally high or abnormally low may be condemned without further examination. But it is clear that the possession of a normal conductivity value is not in itself adequate evidence of the purity of a syrup. U S E F U L N E S S OF T H E METHOD
In Table I X are given the results of analysis of 3 4 syrups as found upon the market in the Provinces of Saskatchewan, Alberta and British Columbia in 191I and 1912. The modified Winton lead number was determined upon the quantity of syrup containing 2 5 grams of dry matter. It will be seen t h a t the conductivity method would condemn 15 of these samples, and t h a t every one of
T H E J O U R N A L OF I N D U S T R I A L AiYD EAVGILVEERINGC H E M I S T R Y
Sept., 1913
TABLEIX-SYRUPS Number
Sold as
Specific gravity
Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Pure Compound Compound Maple flavor Maple flavor
1
2 3 4 5 6 7 S
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
Per cent Moisture
1.309 1.337 1.304 1.315 1.332 1.315 1.323 1.318 1.326 1.332 1.316 1.326 1.344 1.352 1.340 1.323 1.330 1.335 1.315 1.320 1.333 1.327 1.331 1.340 1.324 1.325 1.326 1.329 1.335 1.329 1.337 1.351 1.351 1.339
Standards of purity: Canada. . . . . ., .. Vermont. . . . . . . . . . . Ordinary limits for genuine syrup Minimum. . . , . . . . . . . . . . . . . . . . Maximum. . . . . . . . . , . . . . . . . . . .
36.8 32.2 3 i .6 35.8 33.0 35.8 34.4 35.3 34.0 33.0 35 . 6 34.0 31.1 29.8 31.7 34.5 33.4 32.5 35.8 35 . O 32.9 33.8 33.2 31.7 34.3 34.2 34.0 33.5 32.5 33.5 32.2 30.0 30.0 31.9
35 . o
. . . . .. . .
.
PURCHASED IN THE CANADIAN WEST Modified Winton Per cent Per cent Alkalinity Lead Number Conductivitj Total ash Insoluble ash Alkalinity valu soluble ash insoluble ash (Dry basis) Dry basis Dry basis 0.46 0.11 0.11 23 0.03 0.13 24 0.10 0.13 0.06 0.05 0.09 1.15 113 0.46 0.34 0.29 0.67 1.37 114 0.34 0.52 0.62 0.31 1.99 134 0.47 0.60 0.76 0.34 2.38 150 0 . 4 2 0.58 0.95 0.50 143 1.96 0.46 0.iO 0.44 0.84 2.09 159 0.74 0.42 0.43 0.91 0 .so 79 0.23 0.38 0.41 0.20 133 1.92 0.66 0 50 0.42 0.82 21 0.23 0.10 0 04 0.08 0.07 123 1.40 0.42 0.30 0.38 0.85 90 0.99 0.28 0.18 0.28 0.64 1.61 117 0.45 0.35 0.30 0.72 142 1.58 0.50 0.33 0.48 0.93 152 2.06 0.61 0.38 0.49 0.93 60 0.84 0.26 0.20 0.14 0.33 66 0.83 0.32 0.19 0.23 0.43 85 1.09 0.38 0.22 0.29 0.50 160 2.25 0.72 0.40 0.50 1.09 125 1.68 0.58 0.38 0.33 0.70 93 1.33 0.46 0.21 0.31 0.74 97 1.41 0.42 0.28 0.32 0.54 94 1.29 0.46 0.23 0.30 0.59 145 2.33 0.72 0.43 0.49 1.22 149 2.56 0.83 0.52 0.47 0.93 146 2.11 0.57 0.33 0.50 0.85 1 .26 94 0.48 0.21 0.62 0.32 1.36 113 0.57 0.25 0.65 0.40 0 86 64 0.33 0 16 0.15 0.35 24 0.09 0 20 0.10 0.09 0.04 0.23 0.72 136 0.31 0.14 0.56 0 47 0 . 15 0 .l i 48 0.21 0.13 1 .68 129 0.42 0.30 0 25 0.36
0.60 0.77
0.12 0.23
.. ..
..
.. ..
0.75 1.35
0.23 0.80
0.30 0.66
0.36 0.94
SUMhIARY
A rapid method of detecting adulteration of maple syrup with commercially pure sucrose is described. 2. The “conductivity value” is defined as I O O , O O O times the specific conductivity at 2 5 ’ C. of a mixture of one volume of syrup with two volumes of water. 3. The limits of conductivity value for pure maple syrup are tentatively set at I I O t o zoo. 4. The relation of conductivity value t o ash data is discussed. 5 . The usefulness of the test is illustrated. MACDONALDCOLLEGE QUEBEC
..
..
these ~j is also condemned by a complete analysis. Syrups 3 2 and 34, however, which would pass the conductivity test, are condemned by the other determinations, and Nos. 3, 4 and 2 9 , which are near the limit in conductivity value and which, being of the same brand as Nos. 9, 19, 21, 2 2 , 2 4 and 28, are probably adulterated, are also near the limits of the Canadian standard in respect to the other analytical data and are below the Vermont standard on total ash. When one considers t h a t all the ordinary analytical work on the 1 5 samples might be omitted, the usefulness of the conductivity method is apparent.
I.
747
1.20
110 200
THE COMPOSITION OF DIFFERENT VARIETIES O F RED PEPPERS’ B y L. Ivf. T O L M A N AND L. C. MITCHELL Received M a y 26, 1913 C A Y E N N E OR CHILLI
Geizeral Description.-Cayenne or chilli is a small fruited pepper, a variety of Capsicum f r u t e s c e n s L., a species of Capsicum, which is a genus of the family Solanaceae, indigenous t o the American tropics, but now grown or cultivated in nearly all tropic and subtropic countries. It is characterized by its extreme pungency and the small size of the pods. The leading commercial varieties ( 1 9 1 I) are African and Japanese. The African cayenne or chillies come chiefly from the ports of Mombasa and Zanzibar, British East Africa, and are usually designated in the trade by the name of the port from which shipped; they are from I O to 1 5 mm. in length, dark, dull red in color, and extremely pungent; they are ground for use. A few of the samples contained some unattached stems and calyxes. The Japanese chillies come from the port of Kobe, Japan; these are from 15 to 4 0 mm. in length, bright red in color, clean, containing very few stems or calyxes, and are used chiefly in the unground condition for the preparation of the so-called “chilli sauce.” Cayenne or chilli contains a fixed, bland oil, found I
Authors’ abstract of Bull. 168, Bureau of Chem.. Dept. of Agr.
