PHOSPHORUS. 07 



London in 1680. .It is asserted, indeed, by Kraflft, that he disco. 

 Tered the secret to Mr. Boyle having in the year 1678, carried a 

 small piece of it to London to show it to the royal family ; but 

 there is little probability that a man of such integrity as Mr. Boyle 

 would claim the discovery of the process as his own, and commu- 

 nicate it to the Royal Society, if this had not been the case. Mr. 

 Boyle communicated the process to Godfrey Hankwitz, an apo- 

 thecary of London, who for many years supplied Europe with 

 phosphorus, and hence it went under the name of English phospho- 

 rus. In the year 1774, the Swedish chemists, Gahn and Scheme, 

 made the important discovery, that phosphorus is contained in bones 

 of animals, and they improved the processes for procuring it. 



The most convenient process for obtaining phosphorus seems to 

 be that recommended by Fourcroy and Vauquolin, which we shall 

 transcribe. Take a quantity of burnt bones, and reduce them to 

 powder. Put 100 parts of this powder into a porcelain or stone. 

 ware bason, and dilute it with four times its weight of water. 

 Forty parts of sulphuric acid are then to be added in small portions, 

 taking care to stir the mixture after the addition of every portion. 

 A violent effervescence takes place, and a great quantity of air it 

 disengaged. Let the mixture remain for twenty. four hours, stir, 

 ring it occasionally, to expose every part of the powder to the 

 action of the acid. The burnt bones consist of the phosphoric acid 

 and lime ; but (he sulphuric acid has a greater affinity for the lime 

 than the phosphoric acid. The action of the sulphuric acid uniting 

 with the lime, and the separation of the phosphoric acid, occasion 

 the effervescence. The sulphuric acid and the lime combine toge 

 ther, being insoluble, and fall to the bottom. Pour the whole mix. 

 ture on a cloth filter, so that the liquid part, which is to be received 

 in a porcelain vessel, may pass through. A white powder, which 

 is the insoluble sulphate of lime, remains on the filter. After thii 

 has been repeatedly washed with water, it may be thrown away; 

 but the water is to be added to that part of the liquid which passed 

 through the filter. Take a solution of sugar of lead in water, and 

 pour it gradually into the liquid in the porcelain bason. A whit 

 powder falls to the bottom, and the sugar of lead must be added so 

 long as any precipitation takes place. The whole is again to be 

 poured upon a filter, and the white powder uhich remains is to be 

 well washed and dried. The dried powder is then to be mixed 

 with one.sixth of ill weight of charcoal powder. Put thii mixture 

 VOL. YI, 



