56 Journal of Agricultural Research \'oi. iv, no. i 



The distillates obtained from the kelp were watery in appearance and 

 had a ver}- slightly acid reaction to litmus, although they contained 

 considerable amounts of basic substances. By the Kjeldahl method 3.2 

 gm. of nitrogen was found in the total distillate from i kg. of dried kelp. 

 The tar oils obtained with the distillate floated on the surface, having a 

 specific gravity of 0.984. Their percentage varies from 4 to 7 on the 

 basis of the dry kelp. The gases evolved from the kelp differed from 

 those of the oak and fir in not being combustible during any of the earlier 

 stages of the distillation. The charcoal residue in the retort was soft 

 and of dull-gray color. Leaching experiments indicate that most of the 

 potash may be recovered from the char as a high-grade product. 



Further details of the above work will be considered in a later article. 



SUMMARY 



(i) After a brief resume of the literature, the general chemical com- 

 position of the principal species of Pacific coast kelps is discussed. An 

 extended series of analyses is presented, with experimental data concern- 

 ing the nature of algin and other carbohydrate bodies present. 



(2) The forms of nitrogen in the kelp are considered. Much of the 

 nitrogen is found to be present in nonprotein form. 



(3) Experiments are reported on the form of the iodin, of which only 

 a small proportion is believed to be organically combined. 



(4) The high content of organic sulphur in the kelp is noted and a 

 table of analyses given. 



(5) The economic phases are discussed with reference to feeding value 

 and utilization of organic by-products. The results indicate only slight 

 possibilities of commercial value in these directions. 



(6) Comparative laboratory experiments on the destructive distilla- 

 tion of kelp are presented, and the conclusion is reached that kelp distil- 

 lates are of no practical importance. 



LITERATURE CITED 

 (i) Baich, D. M. 



1909. On the chemistry of certain algae of the Pacific coast. In Jour. Indus, 

 and Engin. Chem., v. i, no. 12, p. 777-787, illus. 



(2) Bauer, R. W. 



1889. Ueber einer aus Laminariaschleim entstehende Zuckerart. In Ber. 

 Deut. Chem. Gesell., Jahrg. 22, p. 618. 



(3) BURD, J. S. 



1915. The economic value of Pacific coast kelps. Cal. Agr. Exp. Sta. Bui. 

 248, p. 183-215, 3 fig. 



(4) Cameron, F. K., Moore, R. B., et al. 



1912. A preliminary report on the fertilizer resources of the United States. 

 U. S.*62d Cong. 2d Sess. Senate Doc. 190, 290 p., 19 pi., maps. 



(5) Cross, C. F., Bevan, E. J., and Beadle, Clayton. 



1903. Cellulose ... ed. 2, 328 p., 14 pi- New York. 



