110 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



There is, however, one mineral which occurs in large quantities 

 and which ofTers some hope of becoming a commercial source of 

 potash. This is the basic alumino-potassic sulphate loiown as 

 jilunito. From it potash alum (known commercially as Roman 

 alum) has long been made in Europe. Our people have shown that 

 potash can be readily obtained from the mineral, and, by special 

 devices which they are studying, probably other by-products can be 

 obtained which will greatly cheapen the cost of the potash. 



The most promising source of potash at present is found in the 

 large areas of kelp groves or sea algae lying along the Pacific coast, 

 growing wherever there is a rocky bottom and a rapid tideway, or 

 beyond the surf line, at depths of from 6 to 10 fathoms. These groves 

 are of various areas from beds of a fraction of an acre to stretches 5 

 miles in length and 2 or more miles in width. During the past sum- 

 mer our people have mapped about 100 square miles of kelp groves 

 in different localities from Puget Sound to Point Loma and have 

 studied the character of the algae as well as the conditions necessary 

 to their utilization commercially and to their maintenance as a per- 

 manent resource of the country. Many more areas yet remain to be 

 studied and mapped, but from what has been accomplished in this 

 preliminary work I am assured that a conservative estimate shows 

 that the kelp which could be gathered from the 100 square miles 

 already surveyed, and without detriment to the permanence of the 

 groves, should yield 1,000,000 tons of chloride of potash annually, 

 worth at least $35,000,000, or about thrice the value of the present 

 importations of potash salts from Germany. 



Satisfactory methods of gathering the kelp are yet to be worked 

 out, but present only minor mechanical difficulties. The value of 

 the kelp is, moreover, probably much greater than represented by the 

 content of potash alone. Our laboratories have shown that iodine 

 and other useful products can be obtained which will pay in large 

 measure, if not fully, for the cost of gathering the kelp and abstract- 

 ing the potash salts. 



Enough has been accomplished to show that this country has within 

 its own borders resources to meet the fertilizer requirements of the 

 present, and for a greatly increased use in the coming years. The 

 saving to our people which can reasonably be expected from these 

 investigations is enormously greater than the cost. These investiga- 

 tions are, however, but little more than begun, although begun very 

 well. That they should be liberally supported and actively prose- 

 cuted can admit of no possible argument. Economic independence 

 of outside nations with large financial gain to the public at the same 

 time is a desideratum justifying the utmost effort of our scientific 

 investigators and strong sympathy and aid from the people's 

 representatives. 



