Preservation of yeast by pressure, freezing, o r storage under water. F. Wi n d is c h (Woch.
Brau., 1929, 46, 349—355).—Samples of five races of bottom-fermentation yeast after storage under water a t 0—1° for 3—4 weeks did not differ significantly from the corresponding fresh yeasts in fermentative and reproductive powers. Under similar conditions, two top-fermentation yeasts deteriorated slightly in the first 2 days, after which their vitality remained constant till the end of the experiment (10 days). Storage under water is better than storage as pressed cake either at 8°, a t 0°, or in the frozen condition. Yeast is not materially harmed by freezing or by even, rapid thawing.
F. E. Day. Influence of tem perature on the p u optim um of diastase during m ashing. W . W in d is c h , P . K o l - BACn, a n d L . v o n B e n e d e ic (W o c h . B r a u ., 1 9 2 9 . 4 6 ,
345—349).— T h e e x is t in g e v id e n c e s h o w s t h a t t h e o p tim u m p n fo r d ia s ta s e r is e s w it h r is in g te m p e r a tu r e , b u t is d e p e n d e n t o n o th e r c o n d itio n s . W in d is c h , K o lb a c h , a n d B a n h o lz e r ( B ., 1 9 2 9 , 6 9 ) h a v e sh o w n t h a t d ia s t a t ic p o w e r is m a te r ia lly le s s e n e d b e lo w p a 5 • 3 i f h y d r o c h lo r ic a c id is t h e a c id if y in g a g e n t , a n d b e lo w ~pn 5 - 2 w h e n la c t ic a c id is e m p lo y e d . A c o m p a r is o n w it h t h e la t t e r n o w s u g g e s ts t h a t w it h a c e tic a c id t h is w e a k e n in g o c c u r s a t a s t ill lo w e r p n v a lu e , su p p o r tin g t h e p r e v io u s c o n c lu s io n t h a t t h is e ffe c t is d u e t o d a m a g e b y t h e a c id t o t h e d ia s ta s e b e fo r e d is s o lu tio n o f t h e b u ffer s u b s t a n c e s fr o m t h e m a lt. D u r in g d e c o c tio n m a s h in g t h e a c id it y d e c r e a se d , in a c a s e q u o te d , fr o m p u 4 "50 a t t h e s t a r t (c o ld ) t o p s 4 - 7 2 a fte r 3 0 m in . a t 4 5 °, fin a lly r e a c h in g p i 4 - 7 6 . A se r ie s o f m a s h e s a t 5 0 °. 6 0 °, a n d 7 0 ° w it h r e a c tio n s a d ju s te d b y t h e a d d itio n o f a c e t a t e b u ffer s o lu tio n s w e r e m a d e u n d e r d e c o c tio n a n d in fu s io n
conditions. The latter method avoids disturbances due to diastatic action a t temperatures below the maximum desired. Fermentable extract and p n were determined on the worts, the latter value having already been shown to agree with that prevailing during the sacchari
fying period. The results of the two mashing methods were in good agreement, and the optimal zones were found to be 4 • 5—5 • 0 at 50°, p i 4 • 8—5 • 4 at 60°, and above p s 5-6 a t 70°. I t is remarkable th a t from a malt mashed for 3 hrs. at 60° and p n 4 • 93 a wort with an apparent fermentability of 95-8%, actually 77-7%,
was obtained. F. E. Da y.
Influence of treatm ent of yeast with varying am ounts of sulphuric acid on the ferm entative power. St a ig e rand Gl a u b it z(Z. Spiritusind., 1929,52, 270—271).—Yeast treated for £, 1, and 2 hrs. with sul
phuric acid of concentrations increasing from 0 ■ 025A7 to 0 • 4N showed a corresponding increase from 15 to 88% in the proportion of cells stained by 0-0001% solution of methylene-blue. In all cases 3 g. of treated yeast yielded about 15-5 g. of carbon dioxide and 19-5 g. of alcohol in 3 days when placed in 12% malt extract.
It is concluded th a t in the purification of yeast by treat
ment with sulphuric acid a sufficient number of cells survive even drastic treatm ent to give a normal fermen
tation if a high pitching rate is used. F. E. Da y.
Im portance of hydrogen-ion concentration for the d istillery. III. W. Di e m a ir and K. Sic h e r t
(Biochem. Z., 1929, 210, 286—295).—Experiments with dari (white Kaffir corn) were carried out under similar conditions to those with maize (B., 1929, 299) and gave similar results. The time of steaming and the period at 4 atm. pressure require to be longer (2-25 hrs.).
During the whole period of fermentation dari mashes resemble closely as regards acidity and state of combina
tion of nitrogen the maize mashes, and are distinct from potato mashes (cf. B., 1928, 797), but dari attains a slightly different p a maximum (4-52, maize 4-58).
P. W. Cl u t t e r b u c k.
Comparative determination of diastatic power b y the m ethods of Lintner and of W indisch and Kolbach. B. La m pe (Z. Spiritusind., 1929, 52, 276).—
Lintner’s method is more subject to errors than is th a t of Windisch and Kolbach. Lintner values of 53, 53, 54, 57, 61, 63, 63, 73,81, and 101 were found to correspond with Windisch-Kolbach values of 215, 247, 269,266, 314, 312, 330, 338, 425, and 487, respectively. As a standard for green malt for distillery purposes, formerly taken as 100 on Lintner’s scale, a Windisch-Kolbach value of 500 is
suitable. F. E. Da v.
Iron content of w ines from the Hérault district.
E. Hu g h e s (Ann. Falsif., 1929,22, 407—410).—Samples of wines in commerce showed an iron content of 15—39 mg./litre for red wines, and 14—24 mg. for white wines.
The high iron content of some wines is due to the corro
sion of iron vessels by sulphites in the wine (cf. Fabre and Brémond, B., 1927, 500). The prohibition of the use of potassium ferrocyanide to remove iron com
pounds is considered justifiable, as with suitable pre
cautions the iron content of wines need not be exces
sively high. H . J. Do w d e n.
B r i t i s h C h e m i c a l A b s t r a c t s— B .
90S C l. X IX .— Fo o d s.
D e t e r m i n a t i o n o f c o p p e r i n g r a p e m u s t a n d w i n e s . G. De b o r d e s(Ann. Falsif., 1929,2 2 , 410—414).
—The customary methods involve the use of large quantities of the material which have to be freed from organic m atter by calcination or by treatm ent with concentrated acids, and these may be a source of error.
The method described is more rapid and exact as it comprises separation of the copper as sulphide followed by electrolysis and determination of the copper by Fontes and Thivolle’s method (Chim. et Ind., 1925, 97).
The reagents required are (i) a standard solution of pure copper sulphate containing 0-0005 g. of copper per c.c.
strongly acidified with 10% sulphuric a c id ; (ii) Fontes and Thivolle’s phosphomolybdic solution (cf. A., 1926, 1282) consisting of 10 g. of molybdic acid in 500 c.c. of water to which are added gradually with repeated shaking 200 c.c. of phosphoric acid, d 1-38. After keeping for 12 hrs. with occasionally shaking, the mix
ture is filtered and boiled for J h r . ; (iii) an 8% solution of potassium permanganate, diluted 100 times at the moment of use. The electrolytic cell consists of a cathode of platinum foil, 1 cm. X 3 cm., supported by a platinum wire close to the bottom of a narrow test- tube, and an anode of platinum wire passing through the bottom of the tube and extending along its axis.
The tube has a side limb inserted immediately above the electrodes as an outlet for washing purposes. A volume of wine containing 0-25—-2-0 mg. of copper is acidified with 5—10% of its volume of concentrated sulphuric acid, and after adding 0-1—0-2 g. of mercuric chloride the solution is brought to the boil and saturated with hydrogen sulphide until cold. The precipitate of sulphur with copper and mercury sulphides is collected, washed with 4% acetic acid saturated with hydrogen sulphide, and calcined. The ash, taken up in a few drops of a mixture of equal volumes of nitric and sulphuric acids, is transferred with washings into the electrolytic cell, bringing the total volume to about 5 c.c. The solution is electrolysed for 1 hr. with a current of 0-2 amp. at 2-0—2-2 volts. After washing with water until the current ceases to-flow, 5 c.c. of reagent (ii) are introduced and the resultant intense blue liquid is transferred to a wide test-tube aud titrated with per
manganate solution (iii) until the blue colour vanishes.
The process is repeated with 2 c.c. of the standard copper solution (i), the amount of permanganate in both cases being proportional to the copper content. Tests made with materials of known copper content showed th at the precipitation of copper is complete and the results are most consistent. H. J. D o w d e n .
See also A ., Oct., 1165, Form ation of i-m alic acid from fum aric acid by A sp erg illu s n ig er (Ch a l l e n g e r and Kl e i n). 1189, Rapid determination of alcohol (Wh a l e y). 1197, Adsorption of am ylase by blood-charcoal and kaolin (Sa b a l it s c h x a and We i d- l ic h). 1199, Inactivation of urease by heavy m etals
(Kit a g a w a). Dried yeast (My r b a c k and v o n Eu l e r).
Fermentation and growth in dry yeast cells
( Ba r t e l and others). Fermentation of yeast at high pressures (Lie s k e and Ho f m a n n). Influence of alcohols on alcoholic fermentation (Ab d e r h a l d e n).
1200, Determ ination of m icro-organism s in s u s pension (Wil l ia m sand others). Butyric acid ferm en
tation of calcium lactate (Sh a p o sh n ik o v and Za k h a r o v). 1203, Effect of p H on vitamin-J3 of yeast
(Wil l ia m s and others).
XIX.—FOODS.
A nalysis of coffee adulterated b y addition of chick peas. J. Fr e z o u l s(Ann. Falsif., 1929, 22, 415—
420).—The presence of roasted peas in coffee is readily detected under the microscope by the blue coloration of the starch granules in the presence of iodine, and by the characteristic forms of the pea cells. Although coffee contains no starch, a determination of the pro
portion of added peas in a mixture, by counting the number of starch granules, is by no means easy or exact.
Determination of reducing sugars after autoclaving and boiling with hydrochloric acid is also unsuitable, since roasted coffee contains a proportion (20—33%) of saccharifiable matter. Samples of roasted peas were found to contain 50-6—52-95% of starch, the propor
tion being reduced to 44-9% by over-roasting. Polari- metric methods were found to be applicable to the determination of the amount of added peas. The material (3 g.), ground to pass 80-mesh, is de-fatted with 50—60 c.c. of ether, dried, and decolorised with 10 c.c. of sodium hypochlorite solution (12°) and 20 c.c.
of concentrated hydrochloric acid. To the mixture are added gradually with continual shaking 2 c.c. of 4%
phosphotungstic acid solution, and after dilution to 100 c.c. the solution is examined polarimetricaily through a 2-dm. tube. A solution of pure pea starch (1 g. in 100 c.c. of hydrochloric acid) gave [oc]p +193-9°. The starch content of peas, calculated on this figure, averaged 49-70% of the dry material. Pentosans and sacchari
fiable celluloses are not determined by this method, hence the slight difference between the polarimetric and saccliarimetric results. Application of the polari
metric method to coffee containing known amounts of added peas gave results accurate to within 5%.
H . J. Do w d e n.
M icro-determ ination of caffeine in coffee. A. C.
Ro t t in g e r (Mikrochem., 1929, Pregl Fest., 308—312).—
A modification of the author’s method (B., 1927, 731) is described, in which 5 g. of coffee are moistened with 5 c.c.
of 10% ammonia solution and extracted by shaking with 100 c.c. of chloroform. Then 20 c.c. of the extract are evaporated, a small fragment of paraffin wax is added, followed by a few c.c. of ether, and the whole is well shaken with a few c.c. of 0-5% hydrochloric acid.
The solution is filtered through cotton wool, the residue extracted four times more with hydrochloric acid, and the united solutions are extracted four times with chloroform. After evaporation of the chloroform the nitrogen in the residue is determined by Kjeldahl’s method, and the amount of caffeine calculated from this. In examining “ caffeine-free ” coffees a larger quantity of material must be taken, and the crude caffeine specially treated to purify it before the Kjeldahl determination is carried out. H . F. Ha r w o o d.
Iodine content of N orw egian fish and fish pro
ducts. G. Lu n d e, K. Cl o ss, H. Ha a l a n d, a n d S. 0.
Ma d s e n (Arsber. ved. Norges Fisk., 1928, 39 p p . ; C h em . Z e n tr ., 1929, i, 1834).
C l. X X .—Me d i c i n a l Su b s t a n c e s ; Es s e n t i a l Oi l s. 909 B ritis h C h em ical A b s tr a c ts —B ,
Preservatives. S a b a l i t s c h k a . D eterm ination of theobrom ine. J a l a d e .—See XX.
See also A., Oct., 1188, Denaturing of proteins
(Tado koro a n d o th e r s ).
Pa t e n t s.
Manufacture of flour. E. A. E i s h e r a n d C. R.
J o n e s (U.S.P. 1.727,429,10.9.29. Appl., 25.5.28. U.K., 27.5.28).—See B.P. 300,537 ; B., 1929, 71.
[Autoclave treatm ent for] preservation of eggs
a n d / o r o t h e r p e r i s h a b l e s . E. Ni e r in c k(B.P.318,534, 6.G.28).
Preservation of [sliced] m eat [under fat]. ( S ir )
T. C le m e n t , and A. C l e m e n t & S o n s , L t d . (B.P. 319,057, 16.6.28).
Antirachitic foodstuffs (B.P. 318,268—9).—See XX.
XX.—MEDICINAL SUBSTANCES; ESSENTIAL OILS.
Determ ination of m ercuric iodide by iodate reactions. F . G. B r o c k m a n (Amer. J. Pharm., 1929,
1 0 1 , 596—601).—Five g. of dry mercuric iodide are mixed in a 100-c.c. flask with 50 c.c. of a 5% potassium cyanide solution and 40 c.c. of distilled water. When the iodide has dissolved, the solution is diluted to 100 c.c. and 10 c.c. are titrated with 0-22V-potassium iodate solution, adding about half the necessary volume a t once (about 13 c.c.); 20 c.c. of hydrochloric acid and 5 c.c. of chloroform are added and the titration is continued, stoppering and shaking the bottle after each addition until the colour imparted to the chloroform by the liberated iodine is just discharged. One c.c. of potassium iodate solution corresponds to 0-02272 g. of mercuric iodide. Results from a series of 12 titrations of one sample showed greatest deviations of + 0 -3 % and —0-2% from the average. E. H. S h a r p l e s .
Silver-ion concentration of colloidal silver germ i
cides. I I I . T itration of soluble iodides in colloidal silver iodide. R. B. S m it h and W. G. C h r i s t i a n s e n
(J. Amer. Pharm. Assoc., 1929, 1 8 , 686—687; cf. B., 1928,547).—The of colloidal silver iodide preparations is usually between 12-5 and 14-0, whereas the silver- ion concentration for pure silver iodide is equivalent to pM 7 ■ 95; showing th at these preparations contain a small excess of sodium iodide. The latter can be determined potentiometrically, using O-OliV-silver nitrate and silver electrodes prepared by treatm ent with hot 1-0% potassium cyanide solution (cf. loc.
cit). In the absence of other conducting materials in the colloidal silver iodide the conductivity follows closely the soluble iodide content. S . C o f f e y .
Preservatives. Detection and pharm acology of alkyl p-hydroxybenzoates. T. S a b a l i t s c h k a (Z.
angew. Chem., 1929, 42, 936—939).—The superiority of the methyl, ethyl, and propyl esters, as against benzoic acid and phenols, is illustrated by a large number of examples. The propyl ester is generally the most effective, but the methyl ester is specific in some cases. The esters are practically free from odour, and are less poisonous than other common preservatives.
The reactions with ferric chloride, Millon’s reagent, and Nickel’s reagent are employed for detection of the esters ; details of the tests are given. S . I . L e v y .
A ssay of ground linseed for non-volatile, ether- soluble extractive. J. L. M a y e r (J. Amer. Pharm.
Assoc., 1929,18, 683—684).—In order to obtain accurate results in the determination of non-volatile, ether- soluble extract the extraction must be carried out for 20 hrs. in a continuous apparatus. S. C o f f e y .
[Novel form of extractor and its application in the] determ ination of theobrom ine and a ssa y of kola preparations. J a l a d e (Ann. Falsif., 1929, 22, 396—405).—The “ perforater ” described is a combination of Soxhlet extractor and separator, for use with solvents heavier than water (e.g., chloroform). A wide cylindrical vessel (A) has its top closed by a reflux condenser, whilst its lower end is sealed to one limb of a narrow U-tube (B). The other limb of B is longer and connects laterally with a wider tube (C) arranged verti
cally and in turn sealed laterally close to the top of A.
In the bottom of A are placed glass wool and beads covered by a layer of chloroform, on which is floated the liquid to be extracted. The solvent is boiled in a flask fitted to the bottom end of tube C and the vapours condensing in the reflux fall gently through the liquid to be extracted, the excess overflowing slowly into the solvent flask by way of tubes B and C. The extraction is very rapid as it occurs a t a high temperature, no emul
sions are formed, and only a small quantity of solvent is needed, this being completely recoverable. In the determination of caffeine in kola products the apparatus gives excellent results. For kola extracts and granules, the material is dissolved in warm water, rendered weakly alkaline with ammonia, and extracted for 4 hrs. with chloroform. In the case of kola nuts, the finely-ground material is macerated on a brine-bath for 1 hr. with dilute sulphuric acid. When the paste due to starch has cleared, the solution is neutralised with caustic soda, rendered feebly alkaline with ammonia, and extracted with chloroform for 4—5 hrs. The anhydrous caffeine crystallises out after removal of the chloroform and is 98% pure. In the determination of theobromine in cacao products, the necessity for making numerous extractions with boiling chloroform is obviated by using the new apparatus. The very finely-ground material (10 g.) is freed from fat by extraction with carbon tetrachloride in a Soxhlet apparatus and after removal of the solvent the powder is suspended in 30—
40 c.c. of water, to which are added 25 c.c. of xV-caustic soda, and the suspension is diluted to 250 c.c. with vigorous shaking. After keeping overnight, 125 c.c. of the supernatant liquid are slightly acidified with hydro
chloric acid and extracted with chloroform for 5 hrs.
The white product after evaporation of the chloroform is freed from traces of caffeine by means of benzene and, after drying, the purity of the theobromine is checked by dissolving in 10 c.c. of AT-sodium hydroxide, to which are added 10 c.c. of Af-acetic acid and 20 c.c. of 0 • 1 iV-silver nitrate. After shaking and keeping overnight, the excess silver is titrated with 0 ■ 1 A'-tbiocyanate (1 c.c. of O'lAT-silver nitrate = 0-0180 g. of theobromine). The apparatus is also very efficient in the determination of alkaloids in materials such as tea and nux vomica.
H . J. D o w d e n .
Preparation of digitalis suitable for injection or oral adm inistration. R. A. H a t c h e r and H . B.
B r itis h C h em ical A b s tr a c ts —B .
910 C l. X X .—Me d i c i n a l Su b s t a n c e s ; Es s e n t i a l Oi l s.
Ha a g (J. Amer. Pharm. Assoc., 1929, 18, 551—563, 670—677).—A detailed study has been made of the preparation of digitalis extract (digisol) by the method advocated in the Netherlands Pharmacopoeia V, in which an aqueous extract is extracted with chloroform, and as a result a method is recommended for the prepara
tion of stable digisol in which digitalis (No. 30 powder) is extracted with eight times its weight of water for 24 hrs. below 25°. The filtrate is extracted for 2 hrs.
with an equal volume of chloroform, and the chloro
formie extract evaporated to dryness. The residue is dissolved in chloroform (20 pts.) and precipitated with light petroleum (375 pts.). The precipitate from 200 mg.
of residue is finally dissolved in 20 c.c. of alcohol and made up to 100 c.c. with sterile water. A second chloro
formie extract contains no active principle. The purified chloroformie residue obtained by repeated precipitation of a chloroform solution of digisol with ether and light petroleum consists mainly of gitalin, with small amounts of digitalin, digitoxin, free genins of the gitalin group, and saponin. The unpurified residue is quite as pure physiologically as any extract from digi
talin, whilst it still retains the necessary solubility in water or normal saline to permit of its being used for intramuscular injection. The less soluble, purified residue is suitable for oral administration. Sterile solutions of digisol in normal saline are stable for over six months in vitro. The gitalin fraction of digisol or the purified extract is unstable in 0-2% hydrochloric acid.
The purified residue obtained from different Specimens of digitalis is of nearly constant activity. Digisol is a more active emetic than tincture of digitalis U.S.P. ; the rates of absorption are similar. The action following the intravenous injection is immediate, but the full effects are not induced so rapidly as in the case of digi
toxin. The persistence of action is greater than th at of strophanthiu or ouabain, bu t less than th a t of digitoxin
or digitalis. S. Co f f e y.
Comparative chem ical exam ination of different brands of acriflavine hydrochloride (acriflavine) and acriflavine base (“ n e u tr a l” acriflavine).
G. W. Co l l in sand A. St a s ia k (J. Amer. Pharm. Assoc., 1929, 18, 659—669).—Comparative chemical analyses have been made on representative samples of acriflavine and “ neutral ” acriflavine from American, English, and French sources. Acriflavine, the hydrated hydro
chloride, loses only its water of crystallisation, which varies from 2-45% to 9-34%, on drying over sulphuric acid in a vacuum, but heating to 100° causes the loss of both water and hydrochloric acid and gives anhydrous diamino-iV-methylacridimum chloride. The hydrochlor
ide can be titrated electrometically with 0-liV-sodium hydroxide ; the p u curves obtained in this titration appear to afford an excellent criterion of the identity and purity of the compound. The samples of “ neutral ” acriflavine differed considerably from one another in appearance, due to the fineness of the powder and the presence or absence of a very small amount of impurity, which may be removed by treatm ent with animal charcoal. The water content varies from 5-6% to 10-17% and the sulphated ash from 2-7% to 11-28%.
The ash is due mainly to the presence of sodium chloride.
The pn value varies from 2-8 to 4-8, and electrometric titration gives a good indication of the purity of the sample. This variation in might account for some of the unfavourable results reported clinically. The results obtained indicate th a t the products of the American manufacturers are quite equal to those obtained from Europe. The term “ acriflavine b ase” is proposed instead of “ neutral acriflavine,” and extensive standard specifications both for the base and acriflavine hydrochloride are given. S. Co f f e y.
Pheno! ether in fennel oil and star anise oil.
E . Ta k k n s (Riechstoffind., 1929, 4, 8—9; Chem.
Zentr., 1929, i, 1755).—Fennel oil contains a compound, CjJT180, b.p. 1470/5 mm., f.p. 21-5°, d15 0-967, a D ± 0°, similar to anethole, which when distilled a t ordinary pressure yields at about 260° anol, C9H100. Star anise oil gives similar results. A. A. El d r id g e.
Australian sandalwood oil com pared w ith the official [oil]. E. Sw a l l o w (J. Amer. Pharm. Assoc., 1929, 18, 684—686).—Australian sandalwood oil from Santalum spicalum contains 90—96% of santalol and is in every way equivalent to the E ast Indian official oil from Santalum album. S. Co f f e y.
M edicinal u se of the essential and pyroligneous oils of C edrus a tla n tica . R. Ma s s y (Bull. Inst. Pin, 1929, Special No., 30—31 ; Chem. Zentr., 1929, i, 1756).—The essential oil has dlh 0-939—0 -945.au +-15°
to +55°, acid value 1 (max.), acid value after acétylation about 20. The tarry oil has d20 less than 1-05, acid
to +55°, acid value 1 (max.), acid value after acétylation about 20. The tarry oil has d20 less than 1-05, acid