proceedings: chemical society 261 



of food in the culture solution was not determinable; he considered that 

 the abundance and variety of organic food in a soil rendered the results 

 entirely independent of any consideration of the composition of the cul- 

 ture solution. The molds were grown in the absence of light. 



The physiological action of certain organic soil constituents: J. J. 

 Skinner. Experiments were made on the effect of salicylic aldehyde, 

 an organic soil constituent, upon the growth of wheat seedlings. Very 

 dilute solutions reduced the growth markedly, or killed the plants. The 

 effect is not neutralized by phosphates, nitrates, or potassium com- 

 pounds. The metabolism of the plants is greatly retarded. Nucleic 

 acid was found beneficial, the more so, the less nitrate was present. The 

 compounds identified in soils have been classified into harmful and bene- 

 ficial. GuanicUn, picoline-carboxylic acid, vanillin, and dihydroxy- 

 stearic acid are harmful, while nucleic acid, histidine, arginine, creatine, 

 creatinine, etc. are beneficial. 



Discussion by Schreiner, Cook, Hunt, Wells, Seidell, Waters, Cameron, 

 Sullivan, and others. The principal points brought out were: The bene- 

 ficial compounds seem to be absorbed unoxidized. Salicylic aldehyde 

 was first found in soil from a rose garden at Mt. Vernon, where the soil 

 was becoming unsatisfactory. The harmfulness of a compound can not 

 be predicted from its composition or constitution. The experimental 

 solutions all contain oxygen in solution. Lime and means for promoting 

 oxidation act as a remedy for dihydroxystearic acid. Remedies for 

 other poisons have not been worked out. The active poison in a given 

 soil cannot be told from the appearance of plants grown in it. Floccu- 

 lation of the soil, better drainage and promotion of oxidizing bacteria 

 all aid in the oxidation of dihydroxystearic acid. 



Chemical changes in heated soils: E. C. Lathrop. A fertile and infer- 

 tile soil from the same locality were compared as to the effects produced 

 by heating under 30 pounds steam pressure (135°). The water soluble 

 constituents were increased. Beneficial compounds were formed, but 

 the production of harmful constituents and the destruction of useful bac- 

 teria more than offset their effect. The net result was a decrease of 

 fertility in the fertile soil. Dihydroxystearic acid was found before 

 heating in the infertile soil, and after heating in both soils. 



Discussion by Schreiner, Sullivan, Sosman, and Cameron. 



The 223d meeting was held at the Cosmos Club February 13, 1913. 

 The following papers were read: 



Tests for absinthe: E. K. Nelson, of the Division of Drugs, Bureau 

 of Chemistry. The various modifications of Legal's test for the detec- 

 tion of absinthe were found to give uncertain results in cases where the 

 oil of wormwood was proportionately small in amount. By conversion 

 of the ketones, including thujone from wormwood, into semi-carbazones, 

 they can be freed by steam distillation from essential oils, such as anise, 

 cloves, etc. The semi-carbazones are then decomposed with dilute acid, 

 the ketones recovered, and Legal's test applied to the material thus puri- 

 fied. In presence of thujone the test is not only more delicate but the 

 characteristic thujone odor can be detected. (Author's abstract.) 



