408 ANNUAL EECORD OF SCIENCE AND INDUSTRY. 



etc. Apatite was recognized as the original source of the 

 phosphoric acid circulating through the animal, vegetable, 

 and mineral kingdoms. Fertilizing with bones was first ap- 

 preciated in England. Hunter, in 1774, recommended it, and 

 experiments were made with bone-dust; and in Sheffield the 

 waste from the manufacture of knife-handles, etc., was used 

 in this way. While experiments were made in Germany in 

 a few localities, and recommended by the government, bones 

 were largely exported to England ; and it w\as shown that, in 

 1822 alone, over 33,000 tons had been sent from the recent 

 battle-fields to London. Although it was noticed that En- 

 glish farmers who employed bone-dust became prosj^erous, 

 and that soils not worth cultivating before thereby grew 

 fruitful, fertilizing by means of guano was the first method 

 adopted by the Germans, and through it they learned to ap- 

 jjreciate their domestic resources in bones. For centuries 

 the manuring of vines and olive-trees with bones in Southern 

 France was regarded as a peculiarity; for tens of years crops 

 of grain, etc., had been doubled in England by application 

 of bone manure ; but the German exporters of bones remained 

 blind believed nothing, and learned nothing. A similar state 

 of affairs existed in Holland, Scandinavia, and Russia, until 

 the movement of 1848. In 1815 Hull imported 8000 tons, 

 and the amount increased by more than 8000 tons each de- 

 cade. With a domestic supply of bones Avorth $2,500,000, 

 England imported to the value of $1,250,000. The introduc- 

 tion of guano checked for a while the bone-mills in Germany; 

 but they soon came into use again, especially in Oberlausitz, 

 characterized by its rational system of agriculture. The 

 erection of sugar manufactories, w4th their demand for bone- 

 black, put an end to the trade with England, and taught the 

 appreciation of bone-meal as a manure, so that, by the mid- 

 dle of 1850, the export had dwindled to 800 tons. With 

 more general use, the increased effect of a higher degree of 

 pulverization was learned, sixteen to twenty hundred weight 

 being used at first to the acre, then eight to twelve, and, aft- 

 er it was possible to convert them into an impalpable pow- 

 der, four to five hundred weight sufficed. The effect was at 

 first attributed to the portion of the bones not only least 

 active, but to some degree preventive of fertilizing effect 

 namely, the fat; fresh bones consisting of 10 per cent, of fat, 



