25^ A»ALTSIS OP HUMAN BONCS. 



Pfobably pot- I think the precipitate formed by an acid in the solution 



la solution^™* ^^ ^^^'^ '^^ *° ^^ aJ-cribed to a small quantity of this metal 



held in solution by carbonate of potash. This effect takes 



place in a still more remarkable manner with caustic 



potash. 



Method of ob- From what has been said it is evident, that, to precipitate 



tainng the ^^ greatest quantity of oxide of gold possible from its mu- 



large-t quanli- ^ i j n r 



tity of precipi. riatic solution by means of alkalis, we must manage so, 



^^'^' that no useless acid remains in the solution; in order that 



less of the triple salt may be formed, on which the alkalis 



have no action. This is effected by evaporations to dryness 



very cautiously conducted. 



■I*he liquor It follows too from what has been said, that the liquors, 



from which from which gold has been precipitated by alkalis, should 



precipitated "0^ ^^ throwu away, for they still contain a considerable 



should not be quantity of the metal. On this occasion 1 may relate a curi- 



thiown away. , i • i i i i • , 



ous antcdote, which shows, that many things are lost some- 

 times in the arts, and in manufactures, from which advantage 



Much thus micrht be derived, if we had the requisite knowledge. For 



lost by jewel- » ..,,,,, - . , , 



lefs, many centuries jewellers had been accustomed to tnrow away 



as useless the waters, with which they cleaned their work, 

 and thus at least two or three thousand francs were annually 

 lost in Paris alone. But since t taught them, that these 

 waters contained gold, and showed them the mode of get- 

 ting it, they preserve them carefully. 



I am at present busy in examining the nature of the 

 gold precipitated from its solution by metallic tin, which is 

 also employed as a medicine; and as soon as I have finished 

 my investigation I shall lay the result before the Society 

 [of Pharmacy at Paris]. 



III. 



Experiments on Human Bones, as a Supplement to the Paper 

 on the Bones of the Ox : iy Messrs. Fourcroy arid Vau- 



fUELIN*. 



Magrtestasup. ^V fiEN in the month of August, 1803, we published 

 ^* *"**"*■ our first paper on the existence of magnesia in bones, we 



* Journal de Physique, vol. LXX, p. 135. 



announced 



