126
,
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
The results for triamine do not indicate a difference in amount for t h e separations of t h e canned fish as made for analysis. I n respect t o t h e different portions of t h e fish analyzed, there does not appear t o be any uniform increase or decrease in t h e amount of triamine in relation t o t h e different periods or temperatures of storage. Monamine and diamine are present in very small amounts and about equal quantities at the end of 1 5 and 1 8 mos. At the end of 32 mos. of storage no monamine was found, while t h e amount of diamine had increased, in some instances being double or more t h a n double t h e quantities found at ~j mos. The temperature of storage apparently has no influence on t h e quantities of q o n a m i n e and diamine found.
11,
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2
relation t o t h e keeping qualities of sardines in respect t o t h e appearance, softness, or texture of t h e fish. It is noted, however, t h a t when cans of t h e long standing commercial packs were opened, t h e fish constituting t h e 4- and 6-yr.-old goods were decidedly soft. These contained t h e largest amounts of amines. Other work has shown t h a t t h e quantity of ammonia and amines in t h e canned sardines has a decided bearing upon t h e detinning of t h e interior of t h e cans. ANIMALPHYSIOLOGICAL CHEMICAL LABORATORY BUREAUOF CHEMISTRY, u. DEPARTMENT O F AGRICULTURE WASHINGTON, D. C.
s.
FUMIGATION WITH FORMALDEHYDE1-A
FOR THE PERMANGANATE-FORMALIN
SUBSTITUTE
METHOD
By DAVIDWILBURHORN Received May 8, 1918
COKCLUSIONS
The d a t a collected in the analyses of old packs of sardines and of t h e experimental packs under known conditions of storage show t h a t marked changes in t h e quantities and relative amounts of ammonia and amines take place in t h e canned fish on standing. I n the case of packs composed of ground meat, these changes could be detected a t I mo. intervals, and amount, in t h e first few months, t o an increase of approximately 5 mg. of alkylamines per I O O g. of material per month. Directly after processing, the volatile alkaline material obtained by t h e method of determination contains practically two-thirds ammonia and one-third alkylamines. During storage a t room temperature t h e proportions appear t o change slowly, until after a long period of standing t h e total alkaline material is about equally divided between t h e ammonia and amines. When stored a t a temperature just above freezing the total quantity of volatile alkaline material produced is much less t h a n t h a t produced when stored at ordinary temperatures. Table I11 shows t h a t t h e samples stored above a freezing temperature for 32 mo. contained in most cases less volatile alkaline material t h a n was found in t h e sardines held a t room temperature for a period of I j mo. The relative amount of ammonia and amines formed a t t h e lower temperature of storage remains t h e same as t h a t composing t h e total volatile alkaline material formed while t h e sardines were standing a t room temperature. The amines composing this volatile alkaline material consisted in most part of triamine which amounted t o practically 80.0 per cent of t h e total. Monamine and diamine are also present during t h e earlier periods of storage (I j and 18 mo.) b u t in much smaller quantities. At t h e end of t h e 32-mo. storage period no monamine was found, b u t t h e diamine had increased 50.0 per cent and over in some instances. The difference in’the rate of formation of ammonia and amines a t a lower temperature of storage and a t room temperature suggests t h a t these changes may be caused in some instances b y bacterial growth. Anaerobic, spore-bearing, gas-forming bacteria which have been found associated with these fish produce both ammonia and amines when grown on media containing fish protein. whether the quantities Of ammonia It is and amines in t h e canned product have .any direct
Vol.
The object of this paper is t o explain, defend, and justify t h e use of bleaching powder and formalin in t h e fumigation of rooms. The common method using permanganate has become prohibitively expensive since the war began. The dichromate method uses an unstable and corrosive acid mixture of formalin and is chemically of low efficiency. The bleaching powder method will be shown in this paper t o be to-day t h e cheapest and best available method for t h e fumigation of rooms. I n t h e past t h e main difficulty in dealing with new methods proposed for fumigations has been t o learn how much formaldehyde gas actually was evolved* and how t h e proposed methods compared with t h e welltried permanganate method. I n this paper t h e method using bleaching powder is compared quantitatively with t h e permanganate method and with t h e dichromate methods, and a simple apparatus and procedure are described whereby t h e yield of formaldehyde gas in any wet method may be determined. The present state of knowledge with respect t o just how much formaldehyde gas must be set free in a room t o get satisfactory germicidal action may be fairly gathered from t h e very different quantities recommended b y several authorities, and brought together in t h e following table: TABLEI-YIELDS
OF
FORMALDEHYDE GAS BY SEVERAL FUMIGATION
METHODS in Which Liquid Formalin Is Used FormalFormalin FormalFormaldehyde used for Chemical dehyde dehyde in t h e air CHAR1000 efficiency of gas gas of the room cu. f t . ACTERISTIC methods given off a t 68’ F. VolumeCHEIIICAL Cc. Grams Cu. ft. Per cent Per cent Permaneanatez 5nn 17 5 75 n 7 in n 3111 ~ e r m a n i a n a t i a : : : : 296 35;6 42.3 1.20 0.120 Dichromate4.. . . 473 13.9 26.5 0.75 0.075 Alum and lime6., 177 10.0 14.0 0.28 0.028 B-Methods in Which Solid Paraform Is Used Formaldehyde Paraform Chemical FormalFormalin the air used for efficiency dehyde gas dehyde gas of the room 1000 cu. f t . of methods given off a t 68” F. VolumeGrams Per cent Grams Cu. f t . Per cent 283: 45.0 122.2 3.49 0.350 25 45.0 10.8 0.31 0.030 45.0 12.9 0 37 0.037 308 A-Methods
.
The calculations for this table were made f r o m the most reliable d a t a available and upon t h e assumption 1 Abstract of a paper presented before Section C, American Association for the Advancement of Science, Pittsburgh, December 29, 1917. * Numbers refer t o corresponding numbers in “References,” p . 129.
Feb., 1919
T H E J O U R N A L 0 F I hrD C S T RI A L A N D E N GI R E E RI Ar G C H E M I S T R Y
t h a t no gas is lost b y leakage, by polymerization, b y solution in condensed or absorbed water, or by a n y other way in which loss may occur in actual fumigations. The efiectiveness of a formalin fumigation as measured by bacteriological tests of record is a n experimental value showing wide variations from a constant value. Experience with both chemical and bacteriological methods leads me t o t h e belief t h a t closer agreement and more reliable generalizations are t o be expected from t h e chemical t h a n from t h e bacteriological tests. I have therefore used chemical methods, taking t h e permanganate-formalin fumigation procedure as set forth b y Rosenau2 as beyond reasonable dispute and as t h e reliable standard procedure for fumigation when measured by bacteriological tests. METHOD O F ASSAY O F FUMIGATIONS
The apparatus used was made from a round batteryjar and a tubulated bell-jar, serving together as a glass gasometer. A glass cylinder open a t both ends supported a glass dish in which t h e reaction between t h e formalin and t h e oxidizing agent was made t o occur. The oxidizing agent in weighed amount was placed i n t h e dish and t h e measured volume of formalin delivered upon it from a suitable pipette through t h e tubulus of t h e bell-jar. 4 jet of water was used t o moisten t h e ground glass surface of t h e tubulus before inserting t h e pipette. When empty, t h e pipette was rapidly withdrawn and t h e glass stopper immediately inserted into t h e tubulus. Although t h e expansion of t h e enclosed air along with t h e hot gases rapidly evolved causes t h e bell-jar t o float up on t h e water, it is easy t o adjust t h e charge and t h e volume of t h e absorption water so as t o avoid all loss of gas. T h e slight pressure upon t h e enclosed reacting mixture due t o t h e weight of t h e floating bell-jar may readily be overcome b y t h e use of a string and pulley a n d a suitable weight. For experiments on a larger scale, one can readily obtain similar glass apparatus of such size as he may wish. I n analysis of t h e absorption water, t h e VolhardRomijn methodg was adopted. It was tested out on dilute formalin solutions containing from 13 t o 400 parts formaldehyde per I O O , O O O . T h e solutions were standardized against known weights of Merck’s “precipitated silver” dissolved in nitric acid. T h e results obtained in testing out this method are given in t h e following table. They fully confirm t h e applicabili t y of t h e Volhard-Romijn method t o t h e determination of small quantities of formaldehyde. TABLE 11-ANALYSES OR FORMALDEHYDE SOLUTIONS BY VOLHARD-
Formalin STOCK taken BOTTLE Cc. 6 5.0 10 2.5 15 1.0 33 0.666 62 0 333
Formaldehyde taken Grams 2.004 1.002 0.401 0,267 0.134
ROMIJNMETHOD Formalde- Formaldehyde hyde in 10 cc found in of each 10 cc b y Valstock solu- hard-Romijn tion tested method -Gram Gram 0.01921 0.02004 0.00973 0.01002 0.00387 0.00401 0,00274 0.00267 0.00134 0.00131
Error by Val.-Rom. method Gram -0.00083 -0.00029 -0.00014 +0.00007
-0.00003
The correction for t h e formaldehyde gas escaping from t h e formalin in t h e dish during t h e time occupied b y a n experiment, when no oxidizing agent is intro-
127
duced into t h e dish, was determined. The value of this error was found t o be small enough t o neglect. There are variations t o be noted among t h e results, as must be expected in heterogeneous systems where stirring is impossible, where t h e oxidizing agent is attacked only superficially, and where contact between t h e formalin and t h e solid oxidizing agent is more or less accidental and incomplete. QUAKTITY O F FORMALDEHYDE GAS EVOLVED
Having a n apparatus adapted t o t h e purpose, and a method of volumetric analysis not t o be questioned, t h e quantity of formaldehyde evolved as gas was determined in each of t h e three processes. (I) T 1% E PERMANGANATE-FORklALIN &I E T H 0 DResults obtained, which are set forth in t h e following table, show t h a t t h e maximum yield is not obtained b y t h e use of those proportions urged by t h e advocates of this method. Using t h e same relative amounts of permanganate and formalin, t h e same value as found by Base was obtained. Contrary t o published statements, t h e maximum yield is not dependent upon the d r y n e s s of the residue.lO The yield increases with t h e weight of permanganate used, as must be expected if t h e area of surface of contact is t h e principal factorll as i t usually is in heterogeneous systems.
TABLE111-WEIGHT-PER
C E N T CHzO YIELDED
FORMALIN METHOD
BY
THE PERMANGANATE-
Final volume t o which absorption water and rinsings were diluted = 725 cc. Temperature of formalin = 22.5’ t o 23.5’ C.
NHiSCN solu-
cent .~~~~byPer-~weight
tion reouired in titrating 25 cc. of the G. KMnOa : Cc. combined abRatio Formalin actually sorption water used in each set and rinsings G. KMn04 : Cc. cc. Formalin used of experiments 1.34 2.500 : 1.250 10.000 : 5 1.26 1.875 : 1.250 7.500 : 5 1.250 : 1.250 1.24 5.000 : 5 1.77 2.500 : 5.000 2.500 : 5(a) 1.73 2.370 : 5 . 0 0 0 2.370 : 5 1.875 : 5.000 1.61 1.875 : 5 1.44 1.500 : 5.000 1.500 : 5 1.18 1.000 : 5.000 1 .000 : 5 Blank No. l . , . . . . . . . . . . . 1.25 1.50 3.14 Blank No, 2 , , . , . . . , . . . . . 5 .OO Reagent b l a n k . . . . . , . . . . 0.00 0.95 ~
~
~~
.
~
~
of the total C H I O used t h a t was yielded as gas
70.9 56.4 52.7 37.4 35.6 30.1 22.4 10.5
..
.. ..
(a) This is the proportion recommended by Rosenau.
(2) T H E DICHROMATE-FORMALIK METHOD-These determinations were made using a specimen of formalin recently acidified with t h e stated amount of sulfuric acid and also treated with t h e quantity of glycerin directed.12 Unless t h e formalin had been recently acidified, I was unable t o prevent t h e separation, as a solid polymer, of some of t h e formaldehyde. This separation occurred more rapidly t h e lower t h e temperature. A specimen of t h e acidified formalin kept one year at room temperature was found, after filtration, t o contain only 84 per cent of t h e formaldehyde originally present.13 A specimen t o which glycerin was also added14 was found after one month a t room temperature t o contain 91.7 per cent of t h e formaldehyde originally present. I n t h e experiments in t h e following table, t h e chemicals were used in t h e proportions recommended by t h e Pennsylvania Department of Health, and also in other
I 28
T H E J O U R N A L OF I N - D 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
ratios between the weight of oxidizing agent and of ormaldehyde. TABLE IV-WEIGHT-PER CENT CHZO YIELDEDBY FORMALIN METHOD
THE DICHROMATE-
Fina1”volume t o which absorption water and rinsings were diluted = 725 cc. Temperature of formalin = 22.5’ t o 23.5’ C. NH4SCN solution required in titrating Ratio 25 cc. of t h e Per cent b y weight G. Na2Crz0;.2HzO : combined absorption of t h e total Cc. Formalin used. water and rinsings CHsO used t h a t Also amounts used cc. was yielded as gas 1.56 : 6 1.18 11.44 1.23 3.12 : 6 ( a ) 13.93 1.56 6.24 : 6 30.35 1.54 12.48 : 6 29.36 2.96 Blank No. 6 . . 0.95 .. Reaxent blank.. (a)This is t h e proportion recommended by the Pennsylvania Department of Health.
........ ......
..
PROCEss-Although 1 had advised this method in 1915 only t o clients of mine a n d had written of i t only in correspondence, t h e process was brought t o Hamilton’s attention with a request for a n opinion upon it. I n 1917 he printed in a paper on “Facts and Fallacies in Disinfection”15 t h e following statements: (3)
THE B L E A C H
FORXALIN
Various improper methods have been proposed and applied
for generating the gas (formaldehyde) from its aqueous solu-
tions. * * * When lime is used as a heating agent * * * * * the lime water slowly but almost completely destroys the aldehyde. * * * * It is also essentially true if calcium hypochlorite is so employed. * * * A prompt and more or less violent reaction occurs when a 40 per cent aqueous solution of formaldehyde is mixed with any of the above-named reagents (lime, caustic soda, calcium hypochlorite), but careful experiments failed to find effective quantities of formaldehyde among the evolved gases. * * * The method employed to determine the amount (of formaldehyde) evolved was essentially t h a t described by Frankforter. * * * * By this method 30 per cent of the theoretical quantity of gas was found to be liberated from a solution by means of potassium permanganate. * * * * * Chlorinated lime under the same conditions appeared to evolve only chlorine compounds, no formaldehyde gas being detected in the aqueous solution collected.
I n the following table are given t h e yields in t h e bleach-formalin process when assayed by the method described under t h e heading, ‘(Method of Assay of Fumigation.” The correction for chlorine compounds evolved from the bleach was determined b y adding absorption water (from assays) t o silver nitrate solution and, without adding a n y acid, filtering off the precipitate and titrating t h e filtrate with sulfocyanate. The precipitate was only sufficient t o produce a t u r bidity and required double filtration t o remove it. T h e correction was found t o range from 0.01t o 0 . 0 2 cc. sulfocyanate solution, which is of the same order as t h e variation among t h e results of comparable fumigation assays by the method I have described. These chlorine compounds failed t o bleach moist litmus paper in experiments conducted on t h e large scale, even when t h e litmus paper was so placed t h a t the outrushing gases had t o pass over i t before mingling with t h e air of the room. Further, this method has already been used in fumigating upward of 3000 rooms, without a single objection or intimation of injury t o fabrics, colors, metals, or anything else, b y the gases. I n the Frankforter and West apparatus used by Hamilton in testing t h e bleach method, the upper p a r t of the flask and apparatus act as a return condenser. Frankforter and West did not recognize this a n d probably Hamilton also did not, for he used t h e apparatus notwithstanding the statements elsewhere
Vol.
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2
in t h e literature’e t h a t call attention t o this important factor. There is no room, of course, for difference of opinion on the fact t h a t formaldehyde can be completely destroyed by oxidation if sealed up with an oxidizing agent, or if heated with one under an efficient return condenser or in a closed bottle. I n fact, Blank and Finkenbeiner’s method” for determining methyl alcohol in commercial formalins rests upon the completeness of such an oxidation under such conditions. TABLE V-WEIGHT-PER CENT CHzO YIELDEDBY
THE BLEACH-FORMALIN METHOD Final volume t o which absorption water and rinsings were diluted = 1000 cc. o r 725 cc. Temperature of formalin = 22.5’ t o 23.5’ C.
NHaSCN
solution required in titratine 25 cc. of &“e Volume Per cent by G. Bleach : combined to weight of Cc. Formalin absorption which CHzO t h e total used Ratio actually used wate: and dilutions G. Bleach : Cc. in each set rinsings were made t h a t was Formalin used of exDeriments cc. cc. yielded as gas 10.0 : 5 2.50 : 1.25 1.12 1000 42.0 7.5 : 5 1.88 : 1.25 1.07 1000 29.6 5.0 :5 1.17 1000 2.50 : 2.50 27.2 2.5 : 5 2.50 : 5.00 1.26 1000 19.1 2.0 :5 2.00 : 5.00 1.28 725 15.1 1.0 : 5 1.18 725 1 .oo : 5 . 0 0 10.5 Blank No. 1 . , 5.00 1000 2.57 Blank No. 2 . . , . . . . . 5.00 3.14 725 .. Reagent blank . . . . . . 0.95 ..
. .....
..
..
RELATIVE
EFFICIENCIES
..
AND
COSTS
OF
THE
THREE
METHODS I N P R A C T I C E
I n the proportions origilzally directed for practical use in actual room fumigations, i t appears from Tables 11, 111, and IV t h a t t h e percentages of the total formaldehyde used evolved as gas are: Per cent 37.5 23.3 13.9
................... .....................
Permanganate-formalin.. Bleach-formalin.. Dichromate-formalin..
.........................
By the permanganate-formalin method, using, as directed, 2 5 0 g. permanganate and 500 cc. formalin for 1000 cu. f t . of room space, the weight of formaldehyde gas evolved into the room is 7 5 g. I n order t o produce this same weight of formaldehyde gas using bleach, one should take t o fumigate a room of 1000 cu. f t . t h e following: Bleaching p o w d e r . . . . . . . . . . . . . . . . . . . 620 g., or l’/a Ib. Formalin.. ......................... 800 cc., or 17/lQpt.
I n order t o produce this same weight of formaldehyde gas using t h e dichromate mixture as recommended b y t h e Pennsylvania Department of Health, one must t a k e t o fumigate a room of 1000 cu. f t . about three times as much of the chemicals as one would use ‘if following the directions laid down by the Department. Taking each method in t h e form and quantity in which i t was recommended for use by its advocates, t h e relative cost per 1000 cu. f t . of room space are found t o be:
...........
Permanganate-formalin method. Dichromate-formalin method . . . . . . . . . . . . . Bleach-formalin method.. . . . . . . .0. . . . . . . . . .
$2.29 0.40 0.29
Taking as t h e criterion for all reliable methods t h e permanganate method as recommended by Rosenau and set forth immediately above, and then making t h e dichromate and bleach methods equal t o i t in yield of grams of formaldehyde gas, the relative costs per 1000 cu. f t . of room-space are:18
Feb., 191.9
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
. .. .. .. ., .. .. .. .. ., .. .. .............
Permanganate-formalin method. Dichromate-formalin method. . Bleach-formalin method
$2.29 1,14 0.39
A question t h a t naturally arises upon consideration of t h e d a t a given for t h e bleach-formalin method is, why not increase t h e proportion of bleach t o formalin? There are two answers t o this. First, t h e reaction becomes extremely violent b y t h e time t h e ratio of 5 parts by weight of bleach t o j parts b y volume of formalin is reached; second, above this ratio notable quantities of chlorine compounds are set free along with t h e formaldehyde gas. It is better t o adhere t o t h e proportions recommended, which proportions both experiment and practical experience in fumigating rooms have demonstrated t o be unobjectionable. It is not advisable t o sacrifice satisfaction for t h e slight saving in cost t h a t could t h u s be realized. SUMMARY
The use of bleaching powder and formalin in fumigating rooms has been proposed in this paper. By the aid of a new and convenient apparatus, this new method has been compared quantitatively with t h e permanganate-formalin and with t h e dichromate-formalin methods. The comparison leads t o t h e conclusion t h a t by using 620 g. bleaching powder and 800 cc. formalin for each 1000 cu. f t . t o be fumigated, as much formaldehyde gas will be thrown off into t h e room as by t h e use of 2 5 0 g. permanganate and joo cc. formalin, and a t only one-sixth t h e cost. The bleach-formalin method is shown t o be only one-third as costly as t h e dichromate-formalin method. It has been shown t h a t t h e printed objections t o t h e bleach-formalin method are without foundation in fact and are contradicted both b y experiment and in practice. REFERENCES I-Relative t o t h e determination of the formaldehyde gas evolved, see Evans and Russell, 13th Report State Board of Health of Maine, p. 234. Also, 14th Report, p. 232. Frankforter and West, J . A m . Chem. Soc., 27, 714. Also, I b i d . , 28, 1234. Base, I b i d . , 28, 964. Doerr and Raubitschek, Wiener klin. Wochschr., 20, 7 19. Fendler and Stiibler, 2. angew. Chem., 21, 2018. Also, Z . H y g . 16. Infektionskrankh. 6 6 , 177. Fendler, Stabler, and Frank, Desinfektion, 4, 228. Auerbach and Plueddemann, .4rb. K a i s . Gesundh., S O , 195. Strunk, Ver6ffent.Geb. ilililitarsanitalswesens, 41, I, 3. Kalaehne and Strunk, Z . Hyg. u . Iitfektionskrankh., 63, 375 a n d 402. Lockermann and Croner, Desinfektion, 2, 1, 549, 59S, a n d 670. Also, Ibid., 4, 393. Dixon, J . A m . Med. Assoc., 1914, 1025. Hamilton, A m . J . Pub. Health, 7 , 282. 2-Rosenau, “Preventive Medicine and Hygiene,” 3rd Ed., p. 1134. Permanganate was proposed in 1902 by Johnson in a paper read before the Sioux Valley Medical Association: the files of this society have been destroyed by fire, and t h e origifal paper is not available. See articles by Evans and Russell and by Rase, cited in Reference 1. For bacteriological tests, see Russell, and also McClintic, Hygienic Laboi~atovyBulletin, U. S. Pub. Health and Mar. Hos. Service, No. 27. 3--IIasseltine, U. S. Public Heelth Reports, 30, 2058. 4--I)ixon, LOC. cit., Reference 1; cf. Rosenau, LOC.cit., Reference 2. 5-Walker, J . A m . Chem. SOC.,27, 227; cf. MacNutt, Manual for Health OfEcers, p. 578, who directs the use of the same chemicals in other proportions. &I,ockermann and Croner, Desinfektion, 2 , 724. 7--l’arkes, “Practical Hygiene,” 4 t h Ed., p. 580. 8-New York City Dept. of Health, quoted by MacXutt, L O C .cit. 9-lZomijn, Z . anal. Chem., 36, 18. Smith, J . Am. Chem. Soc., 26, 1028. Rase, L O G .cit., p 968. See also Evans, LOG.c i t . IO-McClintic, LOC.cit., p. 20. 11-Evans and Russell, LOC.cit,, 14th Report, p. 233. 12-Glycerin is added t o prevent polymerization. It had been used for this purpose in some of t h e early forms of autoclaves for fumigations. See, Newman, “Bacteriology and the Public Health,” 3rd Ed., p. 444. 13-Cf. Dixon, LOC.cit., “LaWall found the solution would be perfectly stable.”
129
proportion, see Rosenau, LOC.cit., p. 1137. J . Pub. Health, 7 , 282. 16-Fendler*and Stubler, Z . angew. Chem., 21, 2021. Evans, L O C . cit., 14th Report, p . 227. I7--Ber., 89, 1327. IS-These costs weie calculated for t h e original paper, read December 29, 1917. The prices were from the New York Journal of Commevce and Commercial Bulletin and were the minimum prices listed for December 24, 1917. I have not recalculated a t later prices as confusion might result, since these costs appeared in the A m . J . Pub. Health, 8 , 161. 14--For
15-Am.
PRIVATE LABORATORY B R Y N M A W R , PENNSYLVANIA
THE PRESENCE OF ACETYLMETHYLCARBINOL IN SACCHARINE SORGHUM SILAGE By W. G. FRIGDEXANN AND C. T. DOWELL Received May 28, 1918
I n t h e course of t h e determination of t h e alcohols i n some saccharine sorghum silage b y t h e Duclaux method, t h a t is, b y t h e distillation of t h e alcohols from a neutral solution, oxidation of t h e distillate with potassium dichromate and sulfuric acid, redistilling, and determining t h e acids b y t h e Duclaux method in t h e second distillate, it was observed by one of us (Friedemann) t h a t a n unusually large amount of acetic acid was present. This led us t o make a further examination of this substance and i t was found t h a t t h e distillate had reducing properties and t h a t i t would form a n osazone. N o further work was done on this until recently when another sample of saccharine sorghum silage was being studied and it was decided t o determine what this reducing substance might be. The work of Balcom‘ on t h e volatile reducing substance in cider vinegar was recalled in this connection, and t h e conditions under which t h e silage was formed and t h e f a c t t h a t it was formed from a cane having a very large amount of sugar led us t o suspect t h a t t h e reducing substance was acetylmethylcarbinol which was found by Balcom t o be present in cider vinegar. It was thought desirable t o compare t h e reducing power of t h e distillate with t h e reducing power of t h e original extract from t h e silage. For this purpcse 2 5 cc. of t h e juice were clarified by treating with lead subacetate and sodium carbonate and centrifuging. T h e reducing power of t h e clarified juice was then determined b y Fehling’s solution and subsequent oxidation and weighing oE t h e copper as cupric oxide. I t was found in this way t h a t t h e reducing power of I O O cc. of t h e silage extract was represented by 1.26 g. of metallic copper. I n order t o get t h e reducing power of t h e distillate, 500 cc. of water were added t o I O O cc. of t h e silage extract and 300 cc. were distilled off; then another 2 0 0 cc. of water were added and t h e distillation continued until t h e total distillate amounted t o 500 cc. The purpose of adding t h e 2 0 0 cc. of water was t o avoid t h e concentration of t h e acid becoming great enough t o act on t h e pentosans t o form furfural. The reducing power of t h e distillate was determined by taking 2 j cc. and proceeding as in t h e case of t h e silage extract. It was found t h a t t h e reducing power of t h e total distillate of 500 cc. was represented by 0.9660 g. of metallic copper. It was 1
J . A m . Chem. Soc., 39 (1917), 309.
