RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECHNY. 



Organic constituents of Pacific coast kelps, D. R. Hoagland ( JJ. S. Dept. 

 Agr., Jour. Agr. Research, 4 {1915), No. 1, pp. 39-58). — The object of this work 

 was to study the organic constituents of California kelps. The following species 

 were examined : Macrocyiitis pyrifera, Nereocystis liietkeana, Pelagophycus 

 porra, Egregia lavigata, E. menziesii, Laminaria andersonU, and Iridcea sp. 



Qualitative examination showed the presence in the kelps of complex com- 

 pounds in a highly colloidal state, but starch and reducing sugars were absent. 

 In all cases a furfurol test was obtained and some samples gave the galactan 

 test, i. e., for mucic acid, after oxidation v>'ith nitric acid. 



The average results of quantitative analyses of kelps are given in the fol- 

 lowing table: 



Average composition of the organic matter of Pacific coast kelp, calculated on 



■whole plant. 



Much of the nitrogen present in kelp is in the nonprotein state. Extractions 

 indicated that one-fifth to one-third was soluble in cold water, which about 

 corresponds to the figures obtained for nonprotein nitrogen. The water ex- 

 tracts from a number of samples of ground kelp were analyzed for acid amid 

 98262°— No. 2—15 2 107 



