944 tliaxsactio.xs of the american institute, 



' Apatite — Its Impoktancb in Domkstic Economy, 



Apatite is a mineral phosphate of liine, similar in character to the 

 bones of animals. This mineral phosphate is most essential to various 

 kinds of vegetable growths, it being taken up from tlic earth and 

 assimilated as one of their essential elements. 



The mineral part of the bones of animals consists to a great extent 

 of phosphate of lime. It must, therefore, naturally i>lay an important 

 part in agriculture ; and, indeed, such for ages has l>een the general 

 impression. Burnt bones lose by calcination one-third part of their 

 weight. This consists of organic matters which is destroyed by the 

 process of combustion. The residue is phosphate of lime, with from ten 

 to twelve per cent of carbonate of lime, and a little fluoride of calcium 

 and magnesia. Apatite, on the other hand, contains ninety per cent of 

 phosphate of lime. The residue is chloride and fluoride of calcium. 

 In the Canadian apatite, about five per cent of silica and a small 

 portion of carbon have been found. Burnt bones are much employed 

 in the manufacture of porcelain. They are mixed to the extent of 

 nearly forty per cent with the other ingredients, such as clay, feldspar 

 and flint. The reason of its employment lies in the fact that the 

 23hosj)horic acid contained in the compound is the vittifiable element, 

 which, at a high temperatui-e, converts the other ingredients into a 

 transparent enamel. Brazil and other countries, where the hides and 

 bones of animals are of- more account than their flesh, supplies the 

 largest number of the latter for fertilizing purposes. Bones are like- 

 wise used in the arts for the manufacture of buttons, combs, and also 

 in the production of phosphoric acid, phosphorus, phosphate of soda, 

 and microcosmic salt. A large amount of bones are utilized by 

 exposure to continued steam, which extracts from them all their 

 grease and other organic matter. They are then ground and sold to 

 the husbandman. The supply of bones is altogether inadequate to the 

 demand, and in order to make up this deficiency other sources of phos- 

 phate of lime have been sought out. Guano, or huano, as it is termed 

 in the language of the Peruvians, which consists of the accumulated and 

 altered excretions of certain kinds of sea fowls, was discovered in the 

 hot climates of Africa and Peru some thirty years ago. It found a 

 ready market in France *nd England. Coprolites were also found in 

 lirge depot-itf, they proving to be the exuvise of animals of former 

 times, or, in other words, the fossil excrements of extinct animals. 

 They contain about sixty per cent of phosphate of lime. The crys- 

 talline mineral phosphate of lime, or apatite, is found in nature in large 



