abstracts: agricultural chemistry 253 



AGRICULTURAL CHEMISTRY.— ^#ec^ oj histidine and arginine as 

 soil constituents. J.J. Skinner. Eighth International Congress of 

 Apphed Chemistry, 15: 253. 1912. 

 In this article attention is directed to the occurrence and distribution 

 of histidine and arginine in soils. The effect of each on plant growth 

 was tested in nutrient culture solution and both were found to be bene- 

 ficial. Plants growing in culture solutions containing only potash and 

 phosphate showed greatly increased growth when histidine or arginine 

 is added. When large amounts of nitrate are present in the culture 

 solution, histidine and arginine produce no appreciable effect on the 

 growth. Plants growing in cultures, whether high or low in nitrate, 

 showed a greatly diminished absorption of nitrate when histidine or 

 arginine was present, whereas the removal of potash and phosphate 

 was practically normal. It appears, therefore, that histidine and argi- 

 nine, like creatinine, creatine, asparagine, and a number of other nitro- 

 genous compounds can replace the effect of nitrate in producing plant 

 growth. J. J. S. 



AGRICULTURAL CHEMISTRY.— (?wanme from a heated soil. E. C. 



Lathrop. Journal of the American Chemical Society, 34: 1260. 



1912. 

 In the course of an investigation on the chemical changes in soil 

 organic matter brought about by heating soil in an autoclave for three 

 hours at 30 pounds pressure, guanine was isolated and identified. The 

 guanine was not found in the unheated soil and arises from the breaking 

 down by heat of higher forms of nitrogenous material, probably nucleic 

 acid. E. C. L. 



AGRICULTURAL CHEMISTRY.— iw/Ztfence of phosphate on the toxic 

 action of cumarin. J. J. Skinner. Botanical Gazette, 54: 245. 

 1912. 

 The toxic action of cumarin to wheat seedlings, and the action of 

 phosphates in ameliorating the toxicity, was studied by growing the 

 plants in nutrient culture solutions. It was found that calcium acid 

 phosphate, mono-sodium phosphate, di-sodium phosphate and tri-sodium 

 phosphate, had a similar effect in overcoming the harmful effect of 

 the cumarin. Calcium and sodium phosphate, the latter under dif- 

 ferent conditions, acid, neutral and alkaline, had the same effect. The 

 effect of the phosphate salts in ameliorating the harmful action of cu- 

 marin is due, therefore, to the phosphate radical, and not to the calcium 

 or sodium or to an acid or alkaline condition. J. J. S. 



