Preparations of Gold lately employed medicinally . 103 



down. One drachm of gold, the solution of which was 

 mixed with ten quarts of water, mixed with a very dilute 

 solution of tin, yielded five drachms and a half of a very 

 fine purple precipitate. 



It does not appear to be a matter of indifference which 

 of these two precipitations is used. When metallic tin 

 is emploved, the precipitate is brown; and the gold, if 

 not in the metallic state, is nearly approaching it. On 

 the contrary, the precipitate produced by muriate of tin 

 at a minimum of oxidation, is of a deep purple colour; 

 and, thouj;h it contains a litile metallic gold, has much 

 iTiore of the oxides of gold and of tin ; whence, it is ob- 

 vious, the efficacy of the two preparations cannot be the 

 same. 



The muriate of gold is so greedy of moisture, that it 

 soon deliquesces : whence it can be employed only in the 

 liquid state; and, as its great causticity renders even this 

 ditficult, Dr. Chrestien thought of uniting it with the mu- 

 riate of soda; thus producmg a triple muriate, less deli- 

 quescent, and less caustic. 



For this purpose, a solution of muriate of gold in di- 

 stilled water, obtained as described above, is to he employed; 

 and it is particularly important that this salt has not an 

 excess of acid. Into this solution is to be poured an 

 aqueous solution of pure decrepitated muriate of soda, so 

 as to combine an equal quantity of the dry salt with the 

 gold dissolved. The two solutions being mixed, the fluid 

 is to be evaporated by a gentle heat in a glass capsule, 

 taking care to stir it well toward the end of the process. 

 When the ntass is sufficiently dry, it is to be powdered 

 while hot in a glass or stone mortar; and the po\\der is to 

 be kept from moisture, which it attracts in a slight degree. 



In this preparation the management of the fire is of great 

 importance : for, if the desiccation of the salt be not carried 

 far enoutfh, it will contain loo much acid ; and, if it be 

 urged too far, it will be in part decomposed, and mixed 

 with a little gold. 



The enlightened physician who extols the use of these 

 preparations, emplovs them externally and iniernally; but 

 recommends them to be.nnxed with other substances, lest 

 their action should be too violent, if given alone. Thus 

 for a long time he did ru)t give the triple muriate of gold 

 and soda, otherwise than mixed with twice its weight of a 

 powder composed of siarcii, charcoal, and the lake used by 

 painters. As llie alumine of the last, however, might take 

 up a portion ol the muriatic acul, and the charcoal might 

 G -A revive 



