224 ANNUAL, REPORT OP THE Off. Doc. 



in a crude way with the beginning of the human race, the second 

 with the investigations of Liebig, just two-thiids of a century ago. 



Some may question whether farming is a science. But if it is 

 not, one of the principal objects of the agricultural chemist is to 

 put it on a scientific basis. When Liebig, the father of agricultural 

 chemistry, began his inves ligations sixty-six years ago, on the sub- 

 ject of nutrition, almost nothing was known upon this subject. At 

 first the progress was slow and few followed this line of chemical 

 research. Other fields offered so much larger returns in a material 

 way for the time and mone}^ expended, that this work was taken up 

 by few. Work done along this line would affect tens of thousands 

 of farmers, and produce millions of money in the country at large, 

 yet the share of profit coming to each individual is comparatively 

 insignificant. A few more bushels of grain raised on each farm is 

 worth millions of dollars to the nation, but only a few dollars to 

 each farmer, therefore comparatively little was done in agricultural 

 chemistry until the Government took up the subject, and now no 

 government worthy of the name exists that does not carry on in- 

 vestigations in agricultural chemistry. 



In speaking upon "What Chemistry is Doing for the Farm," note 

 first that it is trying to discover what is needed by the plant and 

 animal for its highest and quickest development. To do this, the 

 chemist has analyzed every part of plant and animal, and found 

 out the elements and compounds which compose them. He has 

 next tried to learn in what form the elements must be supplied to 

 the growing body to produce the best results. He has then ran- 

 sacked all nature and the products made by man to find the proper 

 materials capable of furnishing the nutriment needed. 



In plant nutrition he has discovered that the only elements not 

 furnished in abundance by most soils, are potash, nitrogen and phos- 

 phorus, but these are absolutely essential and no plant can make a 

 proper development if either of them is wanting. They must also 

 be in an available form; tons of them would be useless if the plant 

 could not use them. On the other hand, they must not be in too 

 great excess, or they will be lost by leaching out of the soil even 

 if they do not kill the plant by their chemical action. A nice equili- 

 brium must be maintained between demand and supply. 



POTASH. 



When the demand for potash was limited, it could be supplied 

 by wood ashes, but as that supply became exhausted, the chemists 

 of Germany put the great mines of Stassfurth on a paying basis 

 and now the larger part of the world's supply is obtained there. 



NITROGEN. 



When it was discovered that nitrogen was nsed by plants and 

 that the most available form was the nitrate, the deposits of guano 

 off the coasts of South America were developed. When this source 

 became exhausted, the nitrate of soda beds of Chili and Peru were 

 opened up. As the price kept advancing, various forms of animals 

 matters were utilized. Fish which were not edible and offal from 

 slaughter houses were turned into fertilizers, furnishing nitrogen, 

 thus using materials which a few years before had no value, and 



