40 Journal of Agricultural Research voi. iv. no. i 



animals, production of sizes, glues, or varnishes, clarification of wines, 

 and paper making. In these studies on the kelp the writer has en- 

 deavored to obtain analytical and other data essential to a more accurate 

 judgment in regard to the above possibilities, at the same time having 

 in mind certain factors of purely theoretical interest. For greater con- 

 venience of discussion the work is described under the following sub- 

 heads: General study of important chemical groups; Forms of nitrogen; 

 Carbohydrates; Cellulose; Hydrolysis; Sulphur content ; Forms of iodin; 

 Economic considerations, including the results of destructive distillation. 



Several varieties of seaweeds have been utilized commercially in Japan 

 for over two centuries. They have served as a basis for the preparation 

 of "Kombu" and other foodstuffs, for glue manufacture, and for the 

 manufacture of "Kanten," in extensive use under the name "agar-agar" 

 (22). The commercially important seaweeds of Japan are, however, 

 of different species and undoubtedly have chemical properties distinct 

 from those of the giant kelps (Macrocystis spp. and Nereocystis spp.) of the 

 Pacific coast. 



The earliest chemical studies of seaweed were made by Stanford 

 (24-3 1 ) on European species about 40 years ago. He described a product 

 obtained from kelp, which he called "algin" or "alginic acid," and for 

 which he claimed remarkable properties. Many uses were suggested for 

 this substance: A sizing material for fabrics, a glue, a food, a water- 

 softening reagent, and various other applications. A theoretical formula 

 was deduced for this so-called "algin," and its elementary composition 

 was stated, but Stanford presented no systematic or detailed chemical 

 studies in support of his conclusions. Furthermore the chemical methods 

 available at that period were very imperfect. 



Since the various papers of Stanford (24-31) were published, only 

 occasional articles of very limited scope have appeared on the organic 

 chemistry of the important marine algae. For the giant kelp of the 

 Pacific coast no systematic analyses or chemical studies of the organic 

 matter have been made, although there are many assertions regarding the 

 presence of valuable substances, such as rubber, useful varnishes, or 

 commercially profitable distillation products. These points will be 

 discussed under their appropriate headings. 



GENERAL STUDY OF IMPORTANT CHEMICAL GROUPS 



The limitations in value of the so-called proximate analyses by the 

 "official" methods are recognized. Such data at present seem, never- 

 theless, to be essential for purposes of general classification and com- 

 parison. In the accompanying tables an extended series of such analyses 

 is presented. The following species of kelp were investigated : Macrocys- 

 tis pyrifera, Nereocystis luetkeana, Pclaqophyciis porra, Egregia laevigata, 

 Egregia menziesii, Latninaria andersonii, Iridaea sp. Analyses were made 



