The Composition of the Pacific Kelps. - Industrial & Engineering

Ind. Eng. Chem. , 1912, 4 (6), pp 431–435. Publication Date: June 1912. ACS Legacy Archive. Cite this:Ind. Eng. Chem. 4, 6, 431-435. Note: In lieu o...
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June,

I 9I 2

T H E JO iYRA:AL OF 1.YD U S T R I A L A N D E N G I N E E K l N G C H E M I S T R i ’ .

same as that of smoking opium. It is evident t h a t satisfactory smoking opium cannot be made from Yen-Shi exclusively, due largely to the lack of the resinous and gummy matters t h a t give to smoking opium its proper consistency. The extract of Yen-Shi is uniformly high in ash, in the above-mentioned instance being 19.00 per cent. I t appears that the ash of opium is largely mater soluble, and a high ash content of a prepared smoking opium is a rather useful indication of the use of YenShi extract. Yen-Shi and Yen-Shi extract has a distinctive and peculiar odor. The recognition of this odor in the finished product is a valuable indication of the use of Yen-Shi. The process of smoking opium is substantially as fol1oTT-s: -1small mass of the material about the size of a pea is taken up on a “dipper” or a small metal rod, known a s a \7en-Hook. This lump is dexterously rotated in the 2ame of a small lamp, usually a peanut oil lamp, until the excessive moisture is driven off and the mass is partly incinerated, or untiI the “pill is cooked.” I t is then placed in the bowl of the opium pipe and held just over the flame of the lamp, and the smoke from the “pill” inhaled. The preparations for smoking occup!- I O t o 1 5 minutes, the actual operation of smoking about 30 seconds. S o attempt is made in this paper t o give a n exhaustive analysis of smoking opium, which is the same in all essentials as gum opium and its products, on which there is already a mass of literature. Further work is being done in this laboratory on the composition of Yen-Shi and Yen-Shi extract, the changes that take place in the smoking process and its quantitative composition, with special reference t o its detection in finished smoking opium. I..IHORATORY,

BUREAUO F INTBRN.4L REVENUE. WASHINGTON. D. C.

THE COMPOSITION OF THE PACIFIC KELPS.’ B y J. W. TURRENTINE.

Received neb. 20, 1912.

Originally the word “kelp” meant the ashes of sea weeds, a product which was lixiviated for the extraction of alkali salts and iodine, I t s preparation constituted an important industry in Scotland and Ireland during the first half of the nineteenth century. The term then came to be applied to the plants from which these ashes were prepared; and a t prese n t I t is used by many t o designate all large, dark colored sea weeds. The most definite sense in which the word is used includes all plants belonging to one of the families of the brown sea weeds, the Laminariaceac. Members of this family are found on both the -Atlantic and Pacific littoral, but certain ones are peculiar to the Pacific. The most important, from an economic standpoint, because of their size and remarkable content of pothssium salts, are the giant kelps. Vhile the various varieties may grow from two t o twelve feet in height, the giant kelps are found

from thirty to two hundred feet in length and have been observed as long as fifteen hundred feet. Comparatively little is known concerninq the composition of kelps, especially the Pacific kelps. The non-volatile residues of the incinerated plant can be analyzed easily, but to determine the relationships and the combinations existing between the so-cdled inorganic and the organic constituents of the live plant is not a simple matter. The composition of the Pacific kelps has been studied by Mr. David M. Bslch, of Coronado Beach, Cal., the pioneer investigator of these kelps, whose interesting article on t h a t subject appeared in THIS J O U R N A I , . ~ He has analyzed the giant kelps of the northern and southern Pacific coast of the United States, the A’ereocysiis Liietkeana, and the Mucrocystis pyrifera and Pelagophycus porra. Within the last few days he has submitted to this Bureau analyses of various other genuses from the Puget Sound region. Samples.-Speciniens of various kelps. 80 in all, were collected for analysis from certain points of Alaska by Mr. E. C. Johnston, of the “Albatross;” from Puget Sound (San Juan Co.), Wash., by Prof. G. B. Rigg, of the University of Washington: from the region of Monterey Bay, Cal., by Prof. F. h1. NacFarland, of the Leland Stanford, Jr., University ; and from the vicinity of San Diego, Cal., b y Captain IV. C. Crandall, of the La Jolla Marine Biological Station, These embraced about thirty different varieties of kelps and included specimens of the same varieties from different localities, of the same variety a t different ages, and of different parts of the same plant. Those from Alaska were mostly of the smaller varieties and weremade up of theentireplant; thosefrom Puget Sound represented various varieties, large and small, and consisted of the entire plant or of special parts of the plants, cut into small pieces and transmitted in the dry state, in ‘glass jars; the same statements apply also to those from Monterey Bay. Specimens from San Diego consisted of part of the two kelps, Macrocystis and Pelagophycus. They were partially dried and p u t in canvas sample sacks f o r transmittal. Further drying took place in transit and in the laboratory, as a result of which the specimens were in the form of hard ancl compact masses, or balls. In sampling, particular care T%-astaken to distribute throughout the whole sample the salts which had crystallized on the surface of the plants in drying and had subsequently fallen oft’. I n some instances it was found more expedient to grind the entire specimen, thus obviating an arbitrary distribution of the effloresced salts. Drying aizd Gripzding.-The samples chosen were dried, a t 103’ C., for at least seven hours. They were then ground in a n iron mortar. If hard ancl woody, they were ground finally to extreme fineness in a ball mill, while, if thin and papery, they were ground with ease in the mortar to the desired fineness,-to pass a sieve of sixteen apertures per linear inch. Balch,

Published by permis?ion of the Secretary of Agriculture.

*

431

THISJ O I J R N ~ L . 1, 7 7 7 (1909).

432

T H E JOURATAL O F I - Y D U S T R I A L

-1Iethod of Analysis.-The method of analysis here described, while possibly faulty in some particulars, mas adopted because of the speed with which analyses would be made thereby. Samples of 0.5 g. or thereabouts, were n.eighed directly into tared platinum crucibles. The crucibles were then placed on a n asbestos covered gauze and heated t o a temperature below dull redness, when destructive distillation took place. The gases evolved a t the mouths of the crucibles were ignited. On the disappearance of the flame the material was thoroughly stirred, with further heating, until all tarry matter had been driven off. Charcoal remained, black or gray in color, and in t h e form of a loose powder, if the temperature had not been carried too high. The char was transferred t o a z o o cc. beaker containing 5 0 cc. water, t h e beaker was covered and the solution evaporated t o less than 2 5 cc. The resulting solution was filtered free of solid matter (the filtrate being caught in a platinum dish), t h e char washed by decantation with hot water, then transferred to the filter and further washed. To t h e filtrate was added a small volume of ammonium carbonate solution t o precipit a t e calcium carbonate, and it was then evaporated t o dryness on a steam bath. Ammonium salts were expelled b y heating for an instant t o dull redness. The residue was taken up with water and the resulting solution filtered into tared platinum dishes ; hydrochloric acid was added, t h e solution evaporated t o dryness on a steam bath, the dishes and their contents were heated again for an instant to dull redness and cooled in a desiccator. The weights of the solids mere taken as soluble salts. This procedure was adopted in order t h a t t h e salts obtained might represent as closely as possible the actual content of soluble salts of the charred kelp, T o have converted them into sulfates b y the addition of sulfuric acid t o the lixiviate would have lessened t h e liability of loss of potassium salts through volatilization, b u t would have changed materially t h e weight of t h e soluble salts. Where no value is attached t o knowledge of the total content of soluble salts, or when one is content t o calculate t h e total soluble salts from a determination of the potassium, sodium, chlorine and sulfate, t h e latter procedure is t o be recommended. The soluble salts were dissolved in water, the solutions transferred t o graduated flasks and diluted to 50 cc. Portions of this, I O cc. in volume, were subsequently analyzed for potassium by the chlorplatinic acid method. The residue of charcoal left on the filter after the final filtration, together n-ith the precipitate caught b y the second filtration, was ignited t o whiteness. The weight was recorded as ash. The sum of the weights of the soluble salts and of t h e aah when subtracted from the weight of the sample gives a value which represents the matter which has been volatilized. The value is recorded as organic matter.

For t h e determination of iodine, two-gram samples were charred and lixiviated in the manner already

AA'D E-\-GI.YEERISG described.

CHEAUISTRY.

June,

1912

Iodine was determined in this solution

by a n adaptation of the method of Bray and MacKay.* The filtered solution was transferred t o a separatory funnel of 2 j o cc. capacity, containing I O cc. of a solution of sulfuric acid ( I cc. conc. H,SO,: 9 cc. H,O) and 10-1; cc. carbon tetrachloride. The solution was titrated r i t h a solution of potassium permanganate previousll- standardized against pure potassium iodide, the manipulation during the standardization being identical with t h a t employed in the actual analyses. From the solution undergoing titration the liberated iodine was removed as fast as formed by shaking with the carbon tetrachloride. Persistence in the solution of the pink color of t h e permanganate was taken as the end point. I t should be pointed out t h a t the iodide solution titrated by permanganate must be free from other substances liable t o oxidation under the conditions observed. In the ignition of kelps t h e sulfur present is liable to appear as sulfide if t h e ignition be carried on a t too high a temperature and in an atmosphere depleted of oxygen. Such a result has not been observed, however, as coming from the distillation of kelp, and i t is believed t h a t when the distillation has been conducted in an open crucible and with thorough stirring, the absence of other reducing agents (than iodides), both organic and inorganic, is assured. This belief was borne out in t h e analysis b y t h e fact t h a t the first drop of permanganate liberated iodine, distinctly visible in t h e solution, and with the complete setting free of the iodine, the next drop or two gave the end point. Whether the above manner of prepafing the solution for titration insured the complete recovery of all t h e iodine is not known. The determination of iodine in organic matter by the Carius method was too difficult, considering the large number of kelp samples analyzed. I n the distillation, some iodine may have been lost through the oxidation of the iodide. Information on this point will have to be acquired through experimentation rather than conjecture. I n order to determine whether iodides remained in the char in recoverable amounts, the char was ignited t o whiteness and the solution of the resulting ash titrated ; only negative results were obtained. Mr. T. C. Trescott, of the Bureau of Chemistry, was so kind as t o determine the nitrogen content of the various kelps. The analyses were made of the oven-dried samples b y the Kjeldahl method. D I S C U S S I O N O F T A B L E O F RESULTS.

In the second column are given the serial numbers of the kelp samples examined. There are four series consisting of four collections of samples secured during the summer of 191 I ; they are designated b!- the R: initial letter of the name of the collector-as, Rigg; 11: Macfarland; and J : Johnston, with the exception of the Crandall collection, which is designated b y the letter S (Station). I n the fourth column are indicated the locations from which t h e samples mere taken. In many intances t h e locus is given with precision. Crandall J . A m Chem. S o c , 32, 1193 (1910).

+

TABLEI. B. ofS. NO. 1

Serial No. R 1

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

R Z

li 18

R 18 R 19 R20 R21 R 22 R 23 R24 R 25 R 26 R27

19 20 21 22 23 24 25 26 27 28 29 30 31 32

Name of kelp. Location. Sereocystis luetkeana Snn Juan Co., \I-ash. Laminaria bullata Agarum fimbriatum Laminaria bullata Nereocystis luetkeana Laminaria saccharina Alaria r a l i d a Sereocystis luetkeana Desrnarestia ligulata, herbacea Laminaria bullata

R 4 R 5 R 6 R i R 8 R 9 R 10

R 11 R 13 R 14

Laminaria saccharina Pleurophycus gardneri Fucus eranescens Egregia menziesii Costaria turneri Agarum fimbriatum Desmarestia ligulata. herbacea Cymathaere triplicata Laminaria saccharina Nereocystis luetkeana Fucus evanescens Cymathaere triplicata Pleurophycus gardneri Egregia menziesii h'eah Bay, Wash. Postelsia palmaeformis Macrocystis pyrifera

R 15

R 16 R 17

R 28 R 29 R30 R32 J 1 I 2

J

3 6

35

J

7

Macrocystis pyrifera

36

J

8

Cystophyllum geminatum

37

J

9

.I

10

M M

1

Alaria lanceolata Halosaccion glandiformis Pastelsia palmaeformis Macrocystis pyrifera Egregia menziesii Macrocystis pyrifera Fucus furcatus Postelsia palmaeformis Gigartina radula Fucus evanescens Nereocystis luetkeana Dictoneuron californicum Costaria turneri Nereocystis luetkeana Gigantina spinosa Laminaria andersonii Macrocystis pyrifera

33 34

J

-/ a_ 76 r-

i i

78 79 80 81 I

Fronds

Fronds

R 12

Pterygophora californica Postelsia palmaeformis Rhodymenia palmata linearis Fucus evanescens macrocephalus Fucus, evanescens, ag. forma Alarra (lanceolata ?)

38 39 40 41 42 43 44 45 46 47 48 59 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74

Descrip. tion of sample. Stipe

2 3 M 4 M 5 M 6 iLI 7 M 8 M 9 M 10 M 11 M 12 M 13 M 14

.

Y

s

1

s

2 3 5 4 5 Pelagophycus porra Macrocystis pyrifera S 5A S 6 S 7 S 8 S 9 S 9A 5 10 S 11 S 12 5 13 S 14 S 15 S 16 S 16 A S 17 Pelagophycus porra 5 17 A 5 17 u S 17 Macrocystis pyrifera S 17 C X S 18 S 19 s 19x S 20 S 20 A Pelagophycus porra Faint trace. d

s

Fronds

Fronds

Stipe Y a k u t a t , Y a k u t a t Bay, Ala. Entire plant Sitka. Baranof Island, Alaska Sitka, Baranof Island, Alaska '' Biorka Island, Symonds Bay, Alaska Portion of plant Biorka Island, Symonds Bay. -4laska Biorka Island, Symonds Bay, Alaska Sitka, Baranof Island, Alaska '' " Sitka, Baranof Island, Alaska Montara Point, Cal. Dried stems Xonterey Bay, Cal. Point Pinos. Cal. Off Point Aulon, Cal. Point Alones, Cal. Fronds Montara Point, Cal. Monterey Bay, Cal. Point Alones, Cal. Thallus Point Pinos, Cal. , Point Pinos, Cal. Point Alones, Cal. Off Point Pinos, Cal. Stipes and Aoat Monterey Bay, Cal. Near Point Pinos. Cal. Stipes and fronds Station 1 Station 2 Station 3 Station 4 Station 5 Station Station Station Station

6 7 8 9

Station Station Station Station Station Station Station

10 11 12 13 14 15

16

Station 1 7

c

Station 18 Station 19

25.7 15.9 12.2 10.4 13.3 16 9 9.2 23.0 13.5 11.0 16.4 17.8 6.9 3.1 13.3 17.0 12.4 6.2 13.4 16.4 16.2 3.1 13.8 7.3 10.3 13.9 19.6 14.0 0.37 20.0 2.8

0.08 0.41 0.12 0.29 O,l5 0.41 0.08

0.17 none

1.01

2.7 2.9

none (I)

3 .O

0.12

3.1

7.3 3.4 6.5 22.8 18.3 11.9 23.0 4.9 9.7 3.9 5.6 19.4 15.3 14.4 26.1 9.2 6.3 15.7 13.4 13.4 13.6 12.1 12.5 13.7 12.3 12.1 12.9 9.8 16.7 14.1 16.9 12.6 17.4 17.4 16.4 8.4 Young plant 19.5 Leaves 15.6 Bulbs 29.9 Stems 18.7 Stems and leaves 12 , 4 10.6

...

7.2

Station 20

.... 22.4

1.29

55.9 36.8 28.7 25.0 35.0 35.6 26.4 51.3 41.9 26.4 35.9 38.4 26.5 20.1 30.4 39.1 29.5 24.3 32.0 36.3 40.4 19.0 34.6 27.0 32.1 29.9 32.5 30.4 14.8 41.1 7.2

41.8 57.4 60 3 60.4 61.5 47.0 66.9 46.2 48.3 64.0 56.4 50.3 34.7 75.3 61.2 54.6 60.2 69.7 58.3 50.4 55.3 77.0 59.7 65.0 60.3 64.4 51.5 49.6

8.9 11.9 14.9 20.6 9.0 12.0 10.3 15.6 15.1 9.4 12.2 9.9 14.5 11.0 10.4 14.8 14.1 12.8 15 5 15.8 7.9 1.5 i.3 14.2 . . . . 9.5 54.9 2.8 91.0

2.3 5.8 11.0 14.6 3.5 17.4 6.7 2.5 9.8 9.6 5.7 11.3 8.2 4.1 8.4 6.3 10.3 6.0 9.7 13.3 4.3 4.0 5.7 8.0 7.6 5.7 16.0 19.2 5.2 4.0 1.8

40.6 25.2 19.3 16.4 21.0 26.7 14.5 36.4 21.3 17.4 25.9 28.1 10.9 4.9 21.0 26.9 19.6 9.8 21.0 25.9 25.6 4.9 21.8 11.5 16.3 22.0 31.0 22.' 0.59 31.6 4.4

....

....

16.3 13.9

12.0 81.1 9 . 3 82.7

2.6 3.4

4.3 4.6

.. . .

13.5

8.8

77.9

8.6

4.7

25.2

20 3

70.6

4.2

4 9

27.0 13.5 24.1 44.5 35.7 27.7 48.3 22.5 29.7 24.5 20.5 42.8 33.1 30.5 55.5 25.9 19.4 35 0 31.2 29.3 30.6 29.6 28.8 30.2 28.9, 29.0 28.5 31.2 36.6 32.2 36.3 30.4 44.1 39.0 41.2 22.1 41 . O 37.38 60.6 40.3 28.3 28.6

15.5 8.1 13.8 8.5 6.8 8.9 7.0 14.8 14.4 18.3 11.7 12.1 8.9 7.7 14.3 14.3 9.4 10.1 10.0 8.1 8.2 10.5 9.0 8.5 9.5 9.9 8.1 15.7 10.2 9. 9.6 10.5 16.6 11.5 l5,3 8.8 10.2 12.8 13.1 10.7 8.7 11.9

64.7 8.3 79.4 7.1 5.8 70.1 3.2 52.3 7.3 57.0 65.6 6.7 51.2 5.5 73.2 4.3 4.3 66.0 72.1 3.4 75.1 4.4 4.1 53.1 6.9 60.0 8.5 61.0 3.9 40.6 70.5 3.6 4.8 45.8 60.9 ' 4 . 1 5.9 62.9 66.7 4.0 64.4 5.0 65.5 4.9 67.3 3.9 6.1 63.7 66.2 4.9 9.2 61.8 6.7 64.8 4.7 65.1 56.7 6.7 4.3 63.5 5.4 ,58.3 64.4 5.2 49.4 6.5 55.7 5.3 50.6 8.1 71.7 6.2 52.4 6.6 6.4 56.2 3.0 36.4 54.4 5.3 6.9 64.8 61.3 10.1

11.5 5.4 10.3 36.0 28.9 18.8 36.3 7.7 15.3 6.2 8.8 30.7 24.2 22.8 41.2 14.5 10.0 24.9 21.2 21.2 21.4 19.1 19.8 21.7 19.4 19.1 20.4 15.5 26.4 22.3 26.7 19.6 27.5 27.5 25.9 13.3 30.8 24.6 47.5 29.6 19.6 16.7

19.2 27.95 46.8

7.7

4.5 5.1 4.8

11.5

1.99

1.99 1.90 2.52 1.66 1.94 0 , l i 1.35 0.12 1.73 0 . 3 5 1.95 0.41 2.01 0.53 1.76 0.12 1.93 0 . 0 6 1.66 0.08 2.35 trace , . . . 0.07 1.95 0 . 0 6 2.25 0.06 1.40 trace 1 . 7 6 0.15 2 . 3 2 none 1.59 trace 1 . 5 6 0.12 1.85 0.07 2.49 0.15 1 . 8 3 0.20 1.81 0.22 2.18

.... ....

0.23

....

1.96

0.26 trace trace

1.95

0.09

0.94 2.32 2.25 1.83 1.42 1.40 2.18 1.53 1.70 2.11 2.10 1.12 1.84 1.77 0.90 0.74 1.17 1.04 1.10 0.81 0.95 0.98 1.56 0.83 0.9 0.995 0.898 1.35 0.95 1.57 1.09 1.54 1.01 1.01 1.63 0.53 1.24 1.04 0:53

.... ....

0.26 0.12 0.32 trace 0.15 trace 0.13 0.12 0.09 trace 0.15 trace 0.6 0.15 0.23 0.29 0.38 0.27 0.24 0.29 0.2 0.17 0.17 0.32 0.17 0.29 0.26 0.26 0.32 0.26 0.29 0.41 0.5 0.27 0.35 0.38 0.38 0.19 0.41 . . . . 0.32 0.53 0.38 0.62 0.41 0.69

....

15.3 11.6 9.4 8.6 14.0

... . . . .

.... 12.4

76.3 67.0 48.4

....

....

.... 34.4

'

'

T H E JOUR'VAL OF I K D C S T R I A L An'D Eln'GI.'\'EERliYG

434

has marked as Stations the points from which his samples were collected, and has "placed" each station in degrees, minutes and seconds, as follows: 1.

Off Pt. L o m a . . . . . . . . . . . . . . . . . .

'I

2.

Off Bird Rock . . . . . . . . . . . . . . . . .

"

3.

La Jolla. .....................

"

4.

San Juan . . . . .

"

5.

Pt. Fermin ....................

"

6.

Malaga C o v e . . . . . . . . . . . . . . . . . .

"

7.

Bet. Pt. Gorda & Las Pitas

"

8.

Summerland..

Station

"

. 'I

................

9. Santa Barbara, outside e 9a. Santa Barbara, inside ed 10. St. Naples.. . . . . . . . . . . . . . . . . . .

....

11.

C. Quemada

12.

Little Caxo.. . . . . . . . . . . . . . . . . . .

"

13.

Anacopa. Wreck of \V. Scott. . .

''

14.

Santa Cruz, Gull Is

.

15.

San Miguel, Cuyler Cove. 1..

I'

16.

Tylers Bight, San Miguel

"

16a. Johnstons Lee, Santa Rosa

"

17.

"

l i a . St. Nicholas I s . . . . . . . . . . . . . . . . .

"

18.

SantaBarbaraIs.. . . . . . . . . . . . .

"

19.

Clemente, \Vest side.

"

20.

Clemente, Smugglers Cove

"

.

I

...........

....

.......

S t . Nicholas.. . . . . . . . . . . . . . . . . .

...

......

32' 39' 30" 117' 16' 32'45' 6" 1 1 7 ' 17' 32O51'30" 1 1 7 ' 16' 6" 33O 27' 117'43' 6" 33'43' 12" 118' 21' 30" 33'48' 36" 118' 24' 26" 34O 14' 20" 119' 15' 34'24' l,5" 1190 35' 45"

34' 25' 12" 119' 56' 45" 34' 27' 24" 1200 7' 34' 26' 15" 120' 24' 30" 34' 0' 55" 119' 23' 22" 33' 56' 30" 119' 49' 15" 34' 3' 10" 1200 21' 34' 0' 33" 120' 24' 15" 330 53' 45" 126' 0' 0" 33' 16' 50" 119' 1' 6" 33O 16' 50" 119'37' 45" 33'28' 6 ' 119' 1' 6" 320 57' 9" 1180 35' 12" 32' 48' 12" 118'23'

Where no statement is made concerning the nature of the sample it should be understood t h a t i t was composed of the leafy parts of a large variety, or the entire plant, of a young, smaller kelp. Thus the samples of the southern Macrocystis consisted, in practically every instance, of branches, bearing fronds and floats. The soluble salts, given in the ninth column, represent the weights of the combined sodium and potassium sulfates and chlorides and the soluble magnesium salts. The solution from which these had been precipitated had been treated with ammonium carbonate and mere probably free from calcium salts, I n the test analyses it was found t h a t there were but negligible amounts of both calcium and magnesium salts in the solution obtained on lixiviating the charred kelp. Whether it is safe t o conclude that the lixiviate from the char of every kelp is so free from calcium and magnesium salts is an open question. I t is the writer's opinion t h a t the question is answerable in the affirmative. In very rare cases did the addition of ammonium carbonate t o the lixiviate produce any precipitation of calcium carbonate; this shows a constant freedom from calcium salts and may be taken, b y analogy, as an'indication of a similar absence of magnesium salts. I n the tenth column the estimated sodium salts

CHEMISTRY.

June,

1912

are recorded. These values are mere estimates and most probably are inaccurate. They are obtained b y subtracting the percentage of potassium chloride from the percentage of soluble salts; were both potassium and sodium present as chloride alone in the absence of magnesium, these values would be accurate. It has been shown t h a t sulphates are present in variable amounts. To calculate the potassium to chloride when i t is present wholly or in part as sulfate, throws the entire error thereby introduced upon the sodium, making it appear disproportionately large. When the average potassium chloride content of the twenty-nine samples of the northern kelps (from Puget Sound) is compared with t h a t of the twentyseven samples of the southern (from the region of San Diego), the respective values being z I , 3 per cent, and 23.4 per cent., it appears t h a t the content of the southern plants exceeds that of the northern. I t is seen, however, t h a t the northern collection comprises numerous varieties not included in the southern, Choosing the four varieties in the northern collection which occur in the greatest quantities (the genuses, Nereocystis, Macrocystis, Postelsia, and Egregia-nine specimens), the average KC1 content is 2 j . 7 per cent. Drawing the comparison still closer and comparing the two genuses of the North considered as a commercial source of potash, Nereocystis and Macrocystis, with the two of the south likewise so considered, Macrocystis and Pelagophycus, the average content of the former (six specimens) is 29.4 per cent. KC1, a value considerably in excess of t h a t obtained for the southern varieties (23.4 per cent.). The average content of the two specimens of Macrocystis from Puget Sound is 2 6 . j per cent.; that of the twenty-two specimens from the South is 2 I . 6 per cent. I t is hardly just to draw conclusions from the last comparison; b u t considered as a whole, indications are t h a t the northern kelps are richer in KC1 than the southern. The average iodine content of the thirty specimens from Puget Sound is 0 . 1 5j per cent. and of the four main varieties (ten specimens) is 0.14 per cent. The average of six specimens of the two giant kelps, the Nereocystis and the Macrocystis, is 0.16 per cent. The average percentage content of the southern kelps is 0.29, a value nearly twice that from the northern kelps. From these figures it appears safe to conclude that the northern kelps are richer in potash b u t poorer in iodine than the southern kelps. The average KC1 and I content of the three giant kelps as derived from the table are: Percentage KCI.

.......... ........ .......

Nereocpstis Macrocystis. Pelagophyyus..

32 6 (av. of 6 ) 2 2 . 2 (av. of 27) 3 1 . 3 (av. OF 5 )

I. 0 . 1 4 (av. of 6 ) 0 . 2 7 (av. of 291 0 . 3 6 (av. of 5 )

I n addition t o the variations in composition between the varieties of kelps it will be noted t h a t there is a marked variation between members of the same genus from different localities and from the same locality. There is also a variation strikingly shown in the case of Pelagophycus (Nos. 72 , 73 and 74)

June, 1912

T H E JOL-R.\-.lL

O F I - V D C S T R I A L AiVD E N G I N E E R I N G CHEi1IISTR Y .

betsween the different parts of a single plant. These differences have been pointed out b y Ba1ch.I Phosphorus.-Phosphorus was determined b y t h e official method proposed for the determination of t h a t element in organic substances. The results obtained are given in the following table: TABLEII.--ANALYSES Serial No.

so 1 2

R R 3 R 4 R 5 M . 6 ?,f

s

7

s S

9

BY J. .%.

CULLES. P206.

Name of Kelp.

15

Nereocystis luetkeana Egregia menziesii Postelsia palmaeformas Macrocyst& burifera Macrocystis pyrifera Nereocystis luetkeana Macrocystis pyrifera Macrocys~ispyrifera

17B

Pelagophycus porra

1 16 27 28 2 9

10

Location.

San Juan Co., \Vash. Neah B a y , Wash. Monterey B a y , Cal.. Point Pinos, Cat. St. Naples, Cal. San Miguel, Cuyler Cove, Cal. St. Nicholas, Cal.

Per cent. 0.70 1.79 1.04 0.81. 1.84 0.83 0.66 0.71 0 51

S~..~l]ur.-Sulfur mas determined as barium sulfate in the lixiviate of the charred kelp and ash combined. The char from two-gram samples was lixiviated in the manner described in a foregoing paragraph and then burned t o whiteness. The ash was dissolved in hydrochloric acid and the resulting solution evaporated t o dryness t o dehydrate silicic acid. The residue was taken up with acid, the solutior, filtered and the filtrate added t o the lixiviate from the char. Sulfuric acid was determined in the combined solution in the usual way. The results are recorded in the following table: TABLEI11

su.

R R i hf 4 M 5 S 6 S 1 -?

so3.

Serial No.

S a m e of Kelp.

6 29 4 12 14

2 0 A

.\-ercocj stas luetkeana Macrocystis pyrifera Macrocystis pyrafera ,Vereocystis luetkeana Macrocystis pyrajera Pelngoghycus porra

Source.

Per cent.

San Juan Co., \*-ash. Neah Bay, Wash. Off P t . Aulon, Cal. Off Pt. Pinos. Cal. S a n t a Cruz, Gull Is.

3.45

Clemente, Smugglers Cove, Cal.

2.33

1.68 2.24 2.42 1 .OS

Orgauic Coitstitzteizts.-Little or nothing is known ,concerning the organic constituents of the Pacific kelps. From the figures in Table I , i t can be seen t h a t the organic matter in them rarely falls below 50 per cent. or exceeds 7 j per cent. On the average they contain about I . 5 per cent. of nitrogen which, if calculated t o protein b y the usual factor, is equivalent to 9 . 4 per cent. protein. This value is about equal t o that, of other sea weeds examined for t h a t constituent. Our knowledge concerning the organic constituents of sea algae in general, from which we may derive some idea of what may occur in the Pacific kelps, may be summed up thus: The simple sugars have been identified in certain algae, b u t they are of rare and scanty occurrence; starch has been said t o occur in .some varieties, but its identification has not been substantiated; mannan and levulose are of rare occurrence; galactan is common and abundant, and pentman is the most abundant of all. BCREAU O F SOILS.

U. S. DEPARTNEXT O F AGRICULTURE. WASHIXGTOS, D. C. 1 L O G . Lit.

435

A NOTE ON THE DETERMINATION OF IODIDES BY DIRECT TITRATION.' B y J . W. TURRENTISE. Received F e b r u a r y 20, 1912.

Bray and MacKay* have described a method for the determination of iodides in the presence of bromides and chlorides wherein the iodine is liberated from the iodides b y standardized potassium permanganate, added titrimetrically, and is extracted as formed b y shaking with successive portions of carbon tetrachloride. When the last of the iodine has been set free, the carbon tetrachloride extract is run off from the supernatant aqueous layer and is shaken with a solution of potassium iodide for the extraction of the iodine. The potassium iodide extract is titrated in the usual way -.vith standard thiosulfate solution. In the analysis of kelps for iodine a method was sought which would admit of the determination of small amounts of iodide with the minimum expenditure of time. For this purpose the iriitial liberation of the iodine was effected by standardized potassium permanganate and the amount of iodide thereby determined. The method then became strictly a direct titration of iodide in the presence of bromide and chloride. The results obtained were satisfactorily consistent, and the rapidity with which determinations could be made b y means of i t was such t h a t this account of the method is deemed warranted. The permanganate solution was standardized against solutions of potassium iodide of known concentration (1.0 g. K I t o 1000 cc. H,O), the iodide of which had been purified by recrystallization and thorough drying. Portions of the standard iodide solution were transferred, in graduated pipets, t o a 2 5 0 cc. dropping funnel; 15 cc. of sulphuric acid solution ( I O cc. conc. H,SO, t o 90 cc. H,O) and I j cc. of carbon tetrachloride were added. For the removal of reducing agents, the carbon tetrachloride had been treated for several hours with iodine which was subsequently removed by shaking with sodium thiosulfate solution. The solution of the permanganate was run in from a burette, and as the titration proceeded the liberated iodine was removed from the aqueous layer b y shaking. With the decrease in the concentration of the iodide in this layer, the solubility of the iodine therein decreased, until, astheend of the titration was approached, the solution became entirely colorless. The persistence for one minute of the pink color of the permanganate was taken as the end point. The procedure was identical with t h a t observed in the actual analysis. At first the color of the carbon tetrachloride layer caused some trouble in discerning the end point, but with experience the trouble disappeared. Bray and MacKay have pointed out t h a t in the direct titration of iodides b y a permanganate solution there is an error introduced b y the incomplete reduction of the last of the permanganate t o a form intermediate between the heptavalent and the divalent condition. This would appear to be due to the del

Published by permission of t h e Secretary of:Agriculture.

J . Am. Chem. S o c . , 32, 1193

(1910).

$ bs

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