680 



SCIENCE 



[N. S. Vol. XXXVII. No. 957 



Isodihydroammoeampliolytio acid was prepared 

 by the method of Noyes and Knight {Jour. Am. 

 Chem. Soc, 32: 1669). In the saponification of 

 ;3-aniidoisocamphoric ester some d-eamphorio imide 

 was formed. Isodihydroaminocampholytie acid 

 forms the same anhydride as dihydroaminocam- 

 pholytic acid ; the free acid does not form an inner 

 salt in solution. By decomposing this acid with 

 nitrous acid, a hydrocarbon, d-campholytic acid, 

 1-trans-dihydrohydroxycampholytic acid and 1-cam- 

 pholytolactone are formed. 1-campholytolaetone 

 on hydrolysis gives 1-cisdihydrohydroxycampholytic 

 acid. The Walden inversion occurs only in the 

 formation of 1-campholytolaetone, which is l.S 

 per cent, of the acid decomposed. 



E. S. Potter and W. A. Noyes : Are Ammonium 



Compounds Atomic or Molecular? 



The authors have shown that in amino campho- 

 nanic acid the amino and carboxyl groups com- 

 bine to form an inner salt. Similar acids, amino 

 dihydrocampholytic, amino homo camphonanic and 

 amino homo dihydrocampholytic, probably do not 

 form this inner salt. The above conclusions were 

 arrived at through a consideration of the rotations 

 of the acids mentioned, their hydrochlorides, so- 

 dium salts. The anhydrides and nitroso deriva- 

 tives of the acids were also prepared. The con- 

 clusion as to the structure of the ammonium inner 

 salt is taken as a refutation of Werner's theory 

 of the structure of ammonium compounds. 



O. A. Beath and Edward Kremers: A Crystal- 

 line Besin Acid from the Digger's Pine. 

 The oleoresin of Pinus sahiniana is of special 

 interest not only because it contains heptane in 

 place of pinene of the corresponding oleoresins of 

 the genus Pinus, but also because its resin acid 

 until recently defied all attempts at crystallization. 

 A crystalline product has been obtained by two 

 different methods. 



C. D. Geidel and Edward Keemers: The Oxida- 

 tion, of Indigo Blue ty Phellandrene "Per- 

 oxide. ' ' 



A preliminary report on the relative capacity 

 for oxygen conveyance of phellandrene as com- 

 pared with pinene and limonene. 



Edward Kremers: Direct Salogen Substitution 

 OS a Laboratory Experiment in Organic Chem- 

 istry. 



Text-books have always emphasized the direct 

 substitution of hydrogen of the methane series of 

 hydrocarbons by halogen. Nevertheless, there pos- 

 sibly does not exist a laboratory manual to-day 



which provides an experiment illustrating this 

 important reaction. This is due, no doubt, to the 

 absence of suitable hydrocarbon material. Such a 

 material, however, can now be provided, if wanted, 

 in the form of normal heptane from either the 

 Diggers pine or Jeffrey pine of California. The 

 substitution experiment can be supplemented by a 

 series of reactions illustrative of Schorlemmer 's 

 classical experiments on the constitution of the 

 paraifin hydrocarbons. 



Carl O. Johns and Emil J. Baumann: Be- 

 searches on Purines. 2-Methylmercapto-G, 8-di- 

 oxypurine and 2-Methylmercapto-6-oxy-8-amino- 

 purine. 



2-Thio-i-amino-6-oxypyTimidine was alkylated in 

 alkaline solution by means of dimethyl sulphate 

 giving 2-methylmercapto-4-amino-6-oxypyrimidine. 

 By means of nitrous acid this substance was con- 

 verted to 2-methylmereapto-4-amino-5-nitroso-6- 

 oxypyrimidine. This latter compound was re- 

 duced to 2-methylmercapto-4, 5-diamino-6-oxypyr- 

 imidine by means of ammonium sulphide. The 

 diamino pyrimidine was heated with urea and 

 gave 2-methylmercapto-6, 8-dioxypurine which on 

 hydrolysis with hydrochloric acid gave uric acid. 

 When the above-mentioned diaminopyrimidine was 

 heated with guanidine thiocyanate it gave 2-methyl- 

 mercapto-6-oxy-8-aminopurine, which could also be 

 hydrolyzed to uric acid. 



Carl O. Johns and Albert G. Hogon : Pesearches 

 on Purines. 2-Thio-6, 8-dioxypurine ; 2, 8-dithio- 

 6 -oxypurine ; a New Method of Preparing Xan- 

 thine and Uric Acid. 



When 2-thio-4-amino-6-oxypyrimidine was heated 

 with urea it gave 2-thio-6, 8-dioxypurine. When 

 the latter compound was boiled with ehloracetic 

 acid we obtained 6, 8-dioxypurine-2-thiogIycollic 

 acid, which on heating with hydrochloric acid gave 

 uric acid. When 2-thio-6-oxypurine was heated 

 with ehloracetic acid we obtained 6-oxypurine-2- 

 thioglycollic acid. On hydrolysis with hydrochloric 

 acid this gave xanthine. 



When 2-thio-4-amiiio-6-oxypyrimidine was heated 

 with urea it gave 2, 8-diothio-6-osypurine. With 

 ehloracetic acid this gave 6-oxypurine-2, 8-dithio- 

 glyeoUic acid. 



biological chemistry section 

 Carl L. Alsberg, chairman 

 I. K. Phelps, secretary 

 J. H. Long: Some Conditions Affecting the Sta- 

 bility and Activity of Certain Ferments. 



