Experiments upon Br. Jamais Powder. I09 



liave been formed bv the combuftion of the fulphur of the 

 crude antimony, is diffipated at a much lower temperature 

 than that to which the innvdcr is expofed. 



Every oxide of antimony with which we are acquainted is 

 \-olatile at a hioh degree of heat: it would therefore be ha- 

 zardous to aUert, that it is polliblc to preferve always the 

 fame proportion of antimony, whatever care may be em- 

 ployed in direding the operation; and a dilhmiiarity in the 

 chemical refult mu(t neceifarily be attended with uncertainty 

 in the medical application. 



To this properly may be added another, no lefs conducive 

 to error. That portion of oxide of antimony which is not 

 volatilized, becomes, in a great meafure, infoluble in all the 

 acids. What the effecl of the gaftric juice may be upon a 

 lubdance w hich relills the aolion even of nitro-n)urialic acid, 

 it is not mv purpofc to determine. It is rulHciont for me to 

 fav, that, as the quantity of infoluble matter in a given quan- 

 tity of Dr. James's powder, prepared at different times, may 

 Vary, the effcA of any dofe alfo may differ according to the 

 proportions of foluble and infoluble matter. 



I look upon it as a fortunate circumllance, that thofe ex- 

 periments and obfervalions which I mentioned in the begin- 

 ning of this paper, exifted as a (landard to which I might 

 refer my own attempts, and by which I might ellimate their 

 validity. Dr. Pearfon has proved, (as by my own experi- 

 ments' I have found,) that in Dr. James's powder about 

 a8 per cent, refilled the adion of evrtry acid. In examining 

 Ibme of the puh'i!: antlmonial'ts of the London pharmaco- 

 poeia, I found the average quantity of iufolable njatter to be 

 about 44 per cenJ. ThTs proportion, however, was liable to 

 confiderable variation *. 



The powder here treated of Is denominated by Dr. Pearfon 

 a triple fait, or a real ternary combination of a double bafis 

 (lime and antimony,) with phofphoric acid. What I have 

 mentioned with regard to the quantity of acid contained in 

 bone or hartfliorn, as being too fniall to faturatc a new por- 

 tion of thefe bales, may throw fome doubts vipjn the polli- 

 bility of any fucfi combination in the prefcnt cafe. But I 

 have made fome more dirc6l experiments, which tend to 

 prove that no fuch comI)ination docs exilt. 



I took fome white o-xide of antimony, (formerly called 



♦ I find, from the information of fcvcral medical gentlemrn, that the 

 {,u!vis anumoniaiii ii generally confidcrcd ai (Irongcr th..t: Dr. James's 

 powder. This Cccms rather exiraurdir.ary, when wc corlidcr that tl)c 

 uiuntityof infoluble muctcr is {rre«rcr in the former than in the latKr ; 

 *ad would almwft U;.d u. i« fufpei it to U the adtivc paxc or the med.cmc 



algaroib 



