478 



SCIENCE 



[N. S. Vol. XXXII. No. 823 



Tns Constituents of the Wa^ of GandeliUa or 



Mexican Wax Plant: G. S. Feaps and J. B. 



Rather. 



j\. hydrocarbon was isolated from this substance, 

 melting at 68°, not very soluble in cold ether or 

 chloroform, soluble in hot, difficultly soluble in 

 hot or cold alcohol. It is probably hentriocon- 

 tane, CsiSm, which has also been found in bees- 

 wax. Tivo other bodies were separated but have 

 not yet been identified. 

 A Polariscopio Method for the Determination of 



Malic Add and its Application in Cane and 



Maple Products: P. A. Yodeb. 



Making use of the fact that uranyl compounds 

 cause a manifold increase in the optical activity 

 of active dicarboxylie hydrosy-acids, the author 

 has developed from extensive original data a 

 method of estimating malic acid in solutions 

 which may at the same time contain a wide range 

 of other substances. The rotatory power of the 

 urani\im-malic-aeid compound was found, for a 

 1 per cent, solution to be — ^29.7° Ventzke for 

 white light and — 28.9° Ventzke for yellow light, 

 while that of the malic acid itself in a 1 per cent, 

 solution is — 0.13. Letting P^the polarization 

 before and P' that after the addition of uranyl 

 acetate, t = the temperature C. and L = the 

 length of the polarization tube in dcm., then, 

 with yellow light 

 per cent, mallic acid = 



(P' — P) X [1 + 0.001(t — 20)] 



— 28.8 X iL 

 For white light substitute 29.6 for 28.8 in the 

 formula. 



Strong mineral acids in the free state or an 

 excess of alkali interfere. Any degree of acidity 

 (concentration of H ions) through the range be- 

 tween the two standards: (1) one third N acetic 

 acid, and (2) one third N acetic acid with one 

 fourth of it neutralized with KOH, is favorable 

 for maximum activity. This degree of acidity 

 may be established in a solution by adding acetic 

 acid or KOH until, with methyl orange as indi- 

 cator, a shade is produced between the shades 

 caused by the above two standards. Or the 

 maximum rotatory effect is found by successive 

 additions of acetic acid or KOH to the solution 

 in the polarization tube and trial polarizations 

 after each addition. A tubulated polariscope 

 tube of special construction is suggested for these 

 trials. At least 1.25 atom U should be present 

 for each molecule malic acid, and more in the 

 presence of certain other organic acids. To sepa- 



rate malic acid from syrups, either precipitate 

 with lead acetate and 3.6 volumes 95 per cent, 

 alcohol for each volume of water, liberating the 

 acid from the lead by H^S, or precipitate with 

 barium acetate and 14 volumes 95 per cent, alco- 

 hol for each volume of water, dissolving then the 

 barium malate in water to separate from the 

 sulphate, phosphate, etc. Add to the barium 

 malate solution acetic acid to get the maximum 

 rotatory activity. 



Tivo cane syrups had 0.02 and 0.04 per cent., 

 respectively, and four samples of maple syrup 

 had 0.49, 0.32, 0.z6 and 0..51, respectively, of 

 malic acid. 



By a similar method for d-tartaric acid, polar- 

 izing with white light and at 27.5° C, 



per cent, tartaric acid = 



P'—P 

 25.16 X iL 



For a mixture of tartaric and malic acids, if 

 n = total c.c. N alkali required to neutralize 

 -100 c.c. of the solution, and m ^ change in polar- 

 ization in degrees Ventzke in a 20 cm. tube with 

 white light and at 27.5° C, then 

 per cent, malic acid = 0.03287m — 0. 01741™, 

 and 



per cent, tartaric acid = 0.03824» -f 0.01949m. 

 Notes on the Determination of Acids in Sugar- 

 cane Juice: P. A. Yodee. 



Data are collected upon which to base methods 

 of separating, estimating and identifying organic 

 plant acids. By a simple form of apparatus im- 

 provised by the author, the succinic, aconitic and 

 lactic acids are readily extracted by ether from 

 their water solutions. The malic, citric and tar- 

 taric acids go over into the extract very slowly. 

 Solubility or precipitability tests were made with 

 the calcium and certain other salts of these acids. 

 As a means of identifying citric acid, Denigfe's 

 acetone dicarboxylie acid reaction is very delicate 

 for citric acid, giving, however, the same results 

 with the preparations of aconitic acid that were 

 on hand. 



In a sample of cane juice partly analyzed were 

 found, per 100 c.c. fresh juice, 0.00314 g. phos- 

 phoric, 0.00004 g. oxalic, 0.00077 g. malic and 

 about 0.05 g. aconitic acids. Sulphuric acid was 

 also present. Tartaric, succinic and citric acids 

 were absent. 

 Biochemical and Toxicological Studies upon a 



Number of Species of Penidllium: C. L. Ais- 



BEEG and 0. F. Black. 



The moulds of the genus Penidllium have been 



