RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECimy. 



An introduction to the study of biological chemistry, S. B, Schryver (Lon- 

 don: T. C. d E. C. Jack, Ltd. [1918], pp. 3-^0, figs. 26).— This volume, which is 

 designed particularly for students of medicine and biology, deals primarily 

 with the structure of materials of which the bodies of living objects are com- 

 posed. The subject matter includes chapters on the general scope of biochemi- 

 cal study ; the identification and analysis of organic compounds ; the " constitu- 

 tion," or " structure," of some of the simpler organic compounds ; stereoisom- 

 erism ; the chief chemical constituents of the animal body ; the methods era- 

 ployed for investigation of chemical changes witliin the animal organism ; and 

 the chemical processes taking place in plants. 



The chemical examination of three species of larkspurs, O. A. Beath (Wyo- 

 ming Sta. Bnl. 120 (1919), pp. 55-88, figs. 16). — This bulletin gives a preliminary 

 and general report of a chemical investigation of three species of larkspurs. 

 Delphinium harbeyi, D. glaucescens, and D. geyeri, with a view to determining 

 the nature of the poisonous principles and Iheir variation in kind and amount 

 in the different species and at different periods of growth. The subject matter 

 is divided into four parts. Part 1 contains a general discussion based upon the 

 literature of the distribution and toxicity of larkspurs, cattle losses from lark- 

 spur, and the characteristic symptoms of larkspur poisoning. Part 2 deals with 

 the experimental methods employed in the chemical investigation, part 3, with 

 the chemical analysis of the three varieties studied, and part 4, with the treat- 

 ment for larkspur poisoning as outlined in U. S. Department of Agriculture 

 Bulletin 365 (E. S. R., 3.5, p. 779). 



In the preliminary examination of the larkspurs, the green plants were 

 macerated with water and the extracts tested for their toxicological value by 

 administration to rabbits through a stomach tube. The toxic substances proved 

 to be alkaloidal and capable of being extracted completely with water, indicat- 

 ing their occurrence in the plant in the form of water-soluble salts. Extracts 

 from the leaves of D. geyeri and D. barheyi were more active than those from 

 the stems and flowers, and those from immature plants of these species from 

 three to four times more effective than those prepared from a similar quantity 

 of mature plants. No fatalities resulted from the extracts of D. glaucescens 

 nor from extracts prepared from plants in the seeding stage of any of the spe- 

 cies. Repeated administration of the poison did not produce immunity in 

 rabbits. 



For the separation and determination of the alkaloids, the three species, 

 with the exception of D. geyeri, were employed at three periods of growth — 

 immature, mature, and seeding stages. The material was air-dried and reduced 

 to a uniform powder, percolated with alcohol, the percolate concentrated, ex- 

 tracted with water, acidified, clarified by filtration and by the use of animal 

 charcoal and potassium sulphocyanid, made alkaline with ammonium hydroxid, 

 and the alkaloids finally extracted with chloroform. The customary separation 

 of the alkaloidal constituents by the use of immiscible solvents was employed. 

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