19 



masses of rounded form, and correspond in size with our New 

 England cobble-stones. They are formed out of the bones and 

 fossil remains by solution, and subsequent aglutination, and 

 rolled into small masses by the action of waves upon ancient 

 sea beaches. I have never been so forcibly impressed with the 

 evidence of design, specific and direct, as when studying these 

 most interesting deposits. No one who has not looked into 

 the subject, can form any adequate idea of the extent of man- 

 ufacture and commerce which has grown out of this discovery- 

 The commerce of the port of Charleston has been immensely 

 increased. Vessels are continually arriving with cargoes of 

 sulphur, guano, fish pomace, etc., and many are departing 

 loaded with the rock and manufactured phosphates. England 

 has thus far been the largest consumer, and English manufac- 

 turers have houses established in Charleston devoted to the 

 interests of the trade. The value of the fertilizers shipped in 

 1870, three years after the discovery, was upwards of two 

 millions of dollars. It is stated that the yearly production at 

 the present time is about 300,000 tons of fertilizers, two-thirds 

 of which is exported to England, and only one-third consumed 

 at home. 



Chemistry has pointed out that not a plant exists upon the 

 earth which has not need for phosphoric acid, and when soils 

 were in danger of losing their normal supply, it brought to 

 view the significant fact that rocks piled almost upon our door- 

 steps held it in inexhaustible quantities. Thus science has 

 benefited agriculture in supplying this element of plant food. 

 What has it done for the others ? 



NITROGEN AND POTASH. 



Nitrogen, the most expensive and hitherto the hardest to 



