I AVD US T R I AL d SD ESGI-YEE R I S G C H E X I S T R Y
Septeinber, 1929
'-
Table 111-Gain or Loss i n Weight a n d Survival Period of R a t s Receiving Varying A m o u n t s of B a r t l e t t Pears a s a Source of Vitamin A DAILY , FEED-
I
COSTROI.
R % \ V PEARS
_ I S G_ 1Grams
Dags
-33 -39 - 17 -35 -39 -10
31 35
c IYSED
1
Grams
i
-38 -2i - 10 -34
,
11
30 24 30
-1; - 4 23
~
l
-
I
- 4 - 4
-22
PE %RS
Days
32 38 8 29 55 60 60 55 60 60
Table IV-Gain or Loss i n Weight a n d Survival Period of R a t s Rec e i v i n t Varying A m o u n t s of B a r t l e t t Pears a s a Source of V i t a m i n B ~
~~~
DAILS FEED-
CANNEDPEARS
I
Ran. PEARS CAXNED PEARS '.1 GRAMAUTO-
CONTROL
Isr.
CLAVED
Gvains
Grams
~
3
:
7
1
Days
Grams
Days
55
-1;
I Grams
I
1
Dags
I Grams
I 1
-25 - 8
51 53
1
20 -27 -14 8
-1s
-
YEAST) Days
60 42 30
60 JJ
An
86 1
were coinmercially calmed n.it,h 110 apparent' loss of vitamin C, provided the oxygen was removed by a suitable procedure. Even when no particular pains were taken t o remove this oxygen, beyond those commonly practiced in commercial canning! the loss of vitamin C mas not great, requiring 20 to 30 grams, the approximate equivalent of 15 t o 20 grams of raw pears. Allowing the Kieffer pears t o ripen and niellow previous to caiiniiig resulted in a commercially canned product in which the vitamin C was appreciably lower. The data do not permit quantitative conclusions because of the large amount necessary to make a vibamin-C-free diet protective. The Bart,lett pears were canned and fed raw only in the ripe state. The vitamin C cont,ent of the canned Bartlett pears was approximately that, of the canned ripened Kieffer pears. Animals receiving 15 granis of canned Bartlett pears were comparable to those receiving 15 grams of raw pears. This suggests that possibly the lower vitamin C content of canned ripened Kieffer pears as compared with the canned green pears is to be ascribed to the ripening and mellowing process rat,her than to the effect of canning, a condition found to be true with apples. Bartlett pears, raw or canned, are relatively low in vitamins A and B, 5 to 7 grams per rat per day in experiments conducted according t o the met,hod of Sherman being sufficient t o maintain life without significant growth over a BO-day period, but, there was a vitamin deficiency manifest in all the animals receiving these amounts. Literature Cited
4nimalz recerxed one
,Tarn
autocia\ed ) e n i t per day
Summary Kieffer pears and Rartlett pears are comparable approximately to apples 111 vitamin C content. In contrast t o the result%reported n ith liome calmed pears, in 1% hich vitamin C was almoqt coinplc~telydestroyed by the open-kettle method and largely by the cold-pack method, Kieffer pears a t the time of hxn e,tiiip, nheii they were still hard and green.
(1) Craven and Kramer, J . .Igr. Research, 34, 385 (1927). ( 2 ) Eddy and Kohman, IND.ENG.CHEX.,16, 52 (1924). (3) Eddy, Kohman, and Carlsson, Ibid., 17, 69 (1925). (4) Eddy, Kohman, and Carlsson, I b i d . , 13, 85 (1926). (j) Eddy, Kohman, and Halliday, Ibid., 21, 347 (1929). (6) Givens and McCluggage, Pvoc. Soc. Exfill. B i d . J l e d . , 18, 164 (1921). ( 7 ) Hess and Unger, J . R i d . Chem., 38, 293 (1919). ( 8 ) Kohman, IND. EX. CHE-M.,15, 273 (1923). (9) Kohman, Eddy, (10) Kohman, Eddy, (11) Kohman, Eddy, (12) Miller, J. Home
and Carlsson, I b i d . , 16, 1261 (1924). and Halliday, I b i d . , 20, 202 (1928). Carlsson, and Halliday, IDid., 18, 301 (1926). Econ., 17, 3 i i (1926).
Evolution of Hydrocyanic Acid from Calcium Cyanide' H. D. Young INSECTICIDE DIVISION,BUREAU OF CHEMISTRY A N D SOILS,WASHINGTON, D. C.
ALCIUM cyanide differsfrom the other salts of hydrocyanic acid used in fumigating for insects in that it does not require the use of an acid to liberate its hydrocyanic acid content, but reacts with the moisture of t'he air for this purpose. I n greenhouse fumigation, in which calcium cyanide finds one of its most important applications, it may be safely assumed t'hat t'liere is always sufficient moisture present to liberate all the combined hydrocyanic acid, but in bulb fumigation 011 the Pacific Coast such is not the case. I t is a matter of importance to know, therefore, just how much water vapor is required to liberate hydrocyanic acid from calcium cyanide of different commercial grades.
C
1 Presented under the t i t l e "Effect of Different Humidities on the Generation of Hydrocyanic Acid Gas from Calcium Cyanide," as a part of t h e Insecticide Symposium before the Division of Agricultural and Food Chemistry a t the 75th hfeeting of the American Chemical Society, St. Louis, M o . , April 16 to 19, 1918. Received April 1 7 , 1929.
This investigation was undertaken to determine the effect of air of various relative humidities in liberating hydrocyanic acid from different commercial grades of calcium cyanide. The method used does not correspond to any commercial practice, but represents an attempt to get the maximum possible yield. d 1-gram sample of material was spread out in a thin layer on a 9-cm. filter paper resting on a perforated support 1.3 em. high. This was placed in an aspirator bottle and a current of air introduced under the support. The temperature was kept within a degree of 26" C. throughout the experiment. The flow of air was regulated by a flowmeter so that 500 cc. mere drawn through the system per minute. The hydrocyanic acid liberated was absorbed by bubbling the air through dilute sodium hydroxide solution. At various intervals this was titrated with standard silver nitrate solution and the quantity of hydrocyanic acid calculated.
I N D U S T R I A L A N D ENGIIVEERING CHEMISTRY
862
limt
lh
VOl. 21, No. 9
Hrs.
The humidity was controlled by passing the air through saturated solutions of different salts (1). The salts used and the humidity given by each were: MATER I A L Calcium chloride Copper nitrate Sodium bromide Sodium chloride Sodium nitrate
HUMIDITY Per cent 26 45 56 73 80
AQCEOUSVAPOR PER LITERO F AIR AT 26' C. ME. 6.6 11.2
13.7 18.2 20.0
Distilled water was used to give 100 per cent relative humidity, and anhydrous calcium chloride to give zero humidity.
It was found that by using two cylinders and passing the air through an approximately 20-cm. column of solution, a flow of 500 cc. per minute could be maintained a t the desired relative humidity. Results
The results obtained with four different commercial calcium cyanides are shown in the accompanying charts.
September, 1929
INDUSTRIAL A S D ENGIXEERISG CHEMISTRY
I n Chart I are presented the data of the calcium cyanide with the smallest particle used, a very fine dust, 80 per cent of it passing through a 200-mesh sieve. It contained calcium cyanide equivalent to 23.49 per cent hydrocyanic acid, and in addition considerable quantities of calcium carbonate and sodium chloride and small quantities of calcium carbide and calcium sulfide. The curve for 80 per cent relative humidity so closely approximates the 100 per cent that it is not shown. With both these humidities 95 per cent of the total hydrocyanic acid content is evolved in 2 hours. With 56 per cent relative humidity 4 hours are required to evolve 95 per cent of the hydrocyanic acid. whereas with 45 per cent relative humidity about 85 per cent evolution is reached in 47 hours, and with 26 per cent relative humidity 38 per cent is evolved in 47 hours. (Because of the experimental difficulties of determining the very small quantities of hydrocyanic acid involved, none of the experiments was carried past 95 per cent.) The material used in obtaining the data shown in Chart I1 was of the same general nature chemically as the preceding. It contained the equivalent of 25.27 per cent hydrocyanic acid. It \vas not so finely ground (about like 'ea sand), 80 per cent of it being retained on an 80-mesh sieve. The evolution of gas was slightly slower than with the more finely divided material, 100 per cent relative humidity evolving 95 per cent of the total hydrocyanic acid in about 31/2 hours instead of 2 hours. The lower relative humidities give approximately the same evolution of gas with both materials. The calcium cyanide the behavior of which is shown in Chart I11 was the same chemically as in the two preceding, containing 25.11 per cent hydrocyanic acid. It mas much coarser, however, consisting of small flakes about 0.8 mm. (1/32 inch) thick and a maximum of 6 by 13 mm. ( l / d by '/z
863
inch). The evolution of hydrocyanic acid was much slower than with either of the preceding. With 100 per cent relative humidity, 95 per cent of the total hydrocyanic acid was evolved in 12 hours (not shown on the chart). With the lower humidities the evolution was very slow, 26 per cent humidity producing less than 10 per cent evolution of hydrocyanic acid in 49 hours. The fourth material used (Chart IV) was very different chemically from the preceding three. It consisted of about 30 per cent calcium cyanide (hydrocyanic acid 17.67 per cent), the rest of the material being calcium hydrate. It was very finely powdered, similar to the material described in Chart I. The results were, for the higher relative humidities, similar to those shown in Chart I. For the lower humidities, however, there was a considerably greater evolution of hydrocyanic acid. With the material described in Chart I, 26 per cent relative humidity produced 38 per cent evolution of the total hydrocyanic acid present, whereas with the material described in Chart IV it produced 60 per cent. The differences shown by the four grades of calcium cyanide examined are very probably to be attributed to differences in the degree of fineness of the material. Summary
With any given calcium cyanide the rate of evolution of hydrocyanic acid increases with increasing relative humidity. With a calcium cyanide, 80 per cent of which will pass through a 200-mesh sieve, commercially satisfactory evolution of hydrocyanic acid (90 per cent or more) will occur in about 2 hours, with a relative humidity of 50 per cent or more. Literature Cited (1) New Jersey Agr Expt. Sta., Ann. Rpt., 1919, p. 442.
Purification and Preservation of Ether for Anesthetic Use' S. Palkin and H. R. Watkins DRUGCONTROL LABORATORY, FOOD,DRUG,AND IXSECTICIDE ADMINISTRATION, U. S. DEPARTMENT OF AGRICULTURE, WASHINGTON, D . C.
Ordinarily ether shows a marked tendency to develop the presence of peroxide and aldehydes during storage. This tendency appears to be evident in ether which has been especially purified even when it is stored in a cool, dark place and access of air is prevented. A process of purification and preservation of ether is here described which has kept the ether in a good state of preservation for over a year, even when exposed to light and elevated temperature, conditions which ordinarily bring about rapid development of aldehyde and peroxide. Such ether, furthermore, has not become contaminated with the preservative agent in any other way. Two types of such agents have been found serviceable, pyrogallol and
permanganate, fixed in very strong alkali and spread over asbestos. A small quantity of asbestos impregnated with either of these agents may be placed in the vessel containing the purified ether. From this the ether may be poured for use without resort to filtration. The purification of ether is carried out by distilling the contaminated ether over either of these agents and passing a fine spray of the condensed ether through a column of strong alkaline solution of either of these agents by means of an apparatus similar to that described by the authors for extraction of liquid by means of immiscible organic solvents (18).
HE marked tendency for the development of aldehyde
these impurities in the low concentration ordinarily met (0.005 to 0.01 per cent peroxide) (90,there can be no question as to the desirability of using for anesthesia only ether of the highest purity obtainable. KO consideration will be given in this paper to the pharmacological studies on the impurities in ether. Compliance with the tests and standards for purity setup by the U. S. Pharmacopeia constitutes the legal requirements for ether. These place maximum limits upon the quantities of aldehyde and peroxide it may contain. Ether
...... ......
T
and peroxide in ether, particularly under the catalytic influence of light, is a matter of common knowledge. The possibility of harmful effects of such impurities in ether intended for anesthetic use has been studied by several investigators (9, 10, 12, 14). While no unanimity of opinion exists with regard to the potential danger of ether containing 1 Presented before the Division of Medicinal Chemistry at the 76th Meeting of the American Chemical Society, Swampscott, Mass., September 10 to 14, 1928.
