MISCELLANEOUS. 817 



Take a quantity of bones ; burn them to white- 

 ness in an open fire, and reduce them to a fine 

 powder. Upon three pounds of this powder, after 

 having been put into a matrass, pour two pounds 

 of concentrated sulphuric acid of commerce ; four 

 or five pounds of water must be afterwards added by 

 degrees, to assist the action of the acid. During 

 the process, the operator must place himself and 

 the vessel so that the fumes of the mixture may 

 be blown from him. The whole is then to be left 

 in a sand-bath for about twelve hours, or more, 

 taking care to supply the loss of water which 

 happens by evaporation. The next day, a large 

 quantity of water must be added; the clear liquor 

 must be decanted, and the rest strained through a 

 cloth or sieve. The residuary matter is to be 

 washed by repeated affusions of hot water till it 

 passes tasteless. The water which has been used 

 to wash out the adhering acid is mixed with the 

 decanted or strained liquor, and the whole fluid is 

 gradually evaporated in a flat earthen bason to the 

 consistence of a syrup. It is then mixed with an 

 equal weight of charcoal powder, and submitted to 

 distillation in an iron or earthen retort. Instead 

 of using a receiver, the neck of the retort may be 

 immersed in a bason of water, to a small depth, 

 and the phosphorus, as it comes over, will fall in 

 drops to the bottom. 



Phosphorus made in this manner is blackish and 

 dirty; it is purified by a second distillation. It 

 may also be prepared from urine by the following 

 method. 



Dissolve as much lead in the nitric acid as it 

 will act upon, and the solution will be nitrate of 

 lead. Pour this into a quantity of urine, and a 

 precipitate will be formed. When no more pre- 



