Chap. 3-1 -Acids of Phofpborus and Amber. i$ 



the bones, and forms felenite, and the phofphoric acid 

 remains free in the liquor. The liquor is decanted off, 

 and the refiduum warned with boiling water j this wa- 

 ter, which has been ufed to wafh out the adhering 

 acid, is mixed with what was before decanted off, and 

 the whole is gradually evaporated. The diffolved fele- 

 nite now cryftallizes in the form of fiiky threads, which 

 are removed; and by continuing the evaporation we 

 procure the phofphoric acid, under the appearance of 

 a white pellucid glafs. When this is powdered, and 

 mixed with one third of its weight of charcoal^ we 

 procure very pure phofphorus by fublimation. The 

 phofphoric acid, however, as procured by the above 

 procefs, is never fo pure as that obtained by oxygenat- 

 ing pure phofphorus, either by combuftion or by 

 means of the nitrous acid. 



The phofphoric acid may be rendered concrete with 

 very little difficulty, by merely exhaling the moifture. 

 It abounds in the animal kingdom, and is not unfre- 

 quent in the vegetable and mineral. In this laft it is 

 found united with lead and iron, as well as with calca- 

 reous earth. 



The acid of AMBER is obtained from the fubllance 

 of that name, by the fimple application of heat. The 

 operation mutt not be carried on too far, or by too 

 ilrong a fire, as the oil of the amber is apt to rife with 

 the acid. The acid is found in a concrete form in 

 the neck of the fubliming velTel ; it is foluble in 

 twenty-four times its weight of cold water, and in a 

 much fmaller quantity of hot water. It pofTefTes the 

 qualities of an acid in a very fmall degree, and only 

 affects the blue vegetable colour very (lightly. 



