July 14, 1922] 



SCIENCE 



55 



vinyl arsines were prepared by the action of 

 acetylene upon arsenic chloride in the presence of 

 aluminum chloride and were separated by frac- 

 tionation under reduced pressure. The following 

 derivatives were prepared: Beta-chloro-vinyl arse- 

 nious oxide, beta-chloro-vinyl arsonic acid, beta- 

 chloro-vinyl di-iodo arsine, beta-chloro-vinyl bi- 

 bromo arsine, hydrated bis-beta-chloro-vinyl ar- 

 senic acid, bis-beta-chloro-vinyl arseuious sulfide 

 and bis-beta-chloro-vinyl arsenious oxide. 



Chemical and orystallograpMc notes on the acid 

 phthalates : Francis D. Dodge. The use of potas- 

 sium acid phthalate as ultimate standard in alka- 

 limetry was suggested by the writer in 1915. This 

 salt and the corresponding salts of sodium, am- 

 monium, lithium and magnesium have since been 

 more carefully examined. Acid salts of the 

 formula, 2MHC H O .CHO (M z= K, NH), 



' S 4 4 S 6 4 ^ ' ' 



were also observed. The acid phthalates crystal- 

 lize- remarkably well, and invited further study. 

 The potassium, sodium, ammonium and lithium 

 salts have been measured. The potassium and 

 ammonium salts are isomorphous, and also show 

 an interesting isomorphism with the corresponding 

 salts of ortho-sulfo-benzoic acid. The rubidium 

 and caesium salts were also prepared, and appear 

 to belong to the same isomorphous group. In 

 optical properties, the crystals of the potassium 

 and lithium acid phthalates proved interesting, as 

 they exliibit crossed axial plane dispersion toward 

 the violet end of the spectrum. The same variety 

 of dispersion is also very well shown by the mixed 

 crystals of potassium and rubidium acid phthal- 

 ates. 



The occurrence of formic acid in essential oils: 

 Francis D. Dodge. A crystalline sediment which 

 had been deposited in a zinc lined container of 

 oil of geranium was found to be zine formate, 

 and its occurrence was explained by the presence 

 of formic acid in the oil. This acid, in combina- 

 tion with the alcoholic compounds as esters, is 

 apparently a normal constituent of the oil, the 

 amount of ester, calculated as geraniol formate, 

 ranging from 9 to 13 per cent. A method was 

 devised for the determination of the acid in oils, 

 and a number of the latter were examined. The 

 relatively large amount of formic ester found in 

 oil of geranium seems to be characteristic, and 

 the determination may be of service in the tech- 

 nical valuation of the oil. 



Catalytic reduction of the C^N complex: 

 DeWitt Neighbors, S. M. Clark, J. E. Miller, 

 A. L. Foster and J. E. Bailey. Lochte and 

 Bailey have recently applied the catalytic method 

 employing colloidal platinum to the reduction of 



dimethylketaziue, Me„C=N— N=CMe,. This 

 reaction has been successfully applied to the re- 

 duction of acetone semiearbazone to i-propylseml- 

 carbazide, of menthone semiearbazone to menthyl- 

 semicarbazide, of camphor semicarbone to bornyl- 

 semicarbazide, and of acetaldehydephenylhydra- 

 zone to phenyl hydrazoethyl. The investigation of 

 i-propylsemiearbazide has been completed. Among 

 the salts prepared are the hydrochloride and the 

 oxalate. Other derivatives made are the nitroso 

 and benzoyl compounds. The latter with caustic 

 soda yields the corresponding i-propylphenyl- 

 hydroxytriazole. With 80 per cent. H.,SO^ 

 i-propylsemiearbazide hydrolyzes to i-propylhydra- 

 zine, previously obtained by Lochte in the reduc- 

 tion of acetone hydrazone. Oxidation of the semi- 

 oarbazide with permanganate in either acid or 

 alkaline solution gives 2-carbonamidoazopropane, 

 NH^ — CO — N=N — CHMe^, along with acetone 

 semiearbazone. The azo compound readily under- 

 goes rearrangement to the hydrazone. 



The preparation of mono- and parahroinacetal- 

 dehyde and their application to synthetic worlc in 

 cellulose chemistry: Harold Hibbert and Harold 

 S. Hill. These substances have been prepared 

 in a state of purity and have been applied to the 

 synthesis of a variety of substiinces closely related 

 to the polysaccharides. 



The electrolytic reduction of crotonaldeliyde : 

 Harold Hibbert and Eoland K. Bead. Using a 

 lead cathode, the principal product is an unsat- 

 urated cyclic aldehyde, apparently 4-aldehydo-2, 3- 

 dimethyl-2, 3-dihydro-E-pentene (cyolopentadiene). 

 The authors discuss the mechanism of this reduc- 

 tion and see in it valuable evidence for Nef 'a 

 vinyl alcohol theory of the aldol condensation. 



Preparation and properties of l-mercaptoiejiso- 

 thiazole and its derivatives: L. B. Sebrell and 

 C. E. BoORD. The preparation of this substance 

 from thiocarbanilide and sulfur, from aniline, 

 carbon disulfide and sulfur, and from both the 

 zinc and ammonium salts of phenyldithioearbamic 

 acid and sulfur were carefully studied and com- 

 pared as to yield, purity of product, etc. This 

 work was extended to the methyl derivatives of 

 l-mercaptobenzothiazole, heretofore unknown, and 

 their preparation and properties described. 



Ahsorption spectra of phenylasophenol and its 

 derivatives in the visible region: C. S. Adams and 

 C. E. BoORD. The absorption spectra of azoben- 

 zene, phenylazophenol, and the substitution prod- 

 ucts of phenylazophenol were studied in both alco- 

 holic and alkaline solutions. The shift in the 

 absorption band due to position isomerism, varia- 

 tion in the dye concentration, changes in the 



