1821.] Mr. Phillips's Reply to Dr. Ho-pe. 33 



which I recommended in my examination of the London Phar- 

 macopoeia is preferable to that which you have adopted from the 

 former editions of your Pharmacopoeia. Your process consists 

 in deflagrating a mixture of equal weights of nitre and sulphuret 

 of antimony, the white crust formed at the surface being sepa- 

 rated from the red under part ; the latter is to be reduced to a 

 very fine powder, frequently washed with warm water, dried, 

 and then boiled in water with an equal weight of bitartrate of 

 potash. 



The objection which I made to this process is, that unless the 

 sulphuretted oxide, formerly called crocus aulimonii, thus prepared, 

 be made to undergo the troublesome process of levio-ation or 

 elutriation, it is very difficult to cause the tartar to dissolve a 

 sufficient quantity of it. I prepared some of this sulphuretted, 

 oxide in the manner directed, and having reduced it to an 

 extremely fine powder, and repeatedly washed it, I boiled 100 

 parts of it in water with an equal weight of tartar dining a much 

 longer time than you direct, in order to insure their mutual action, 

 to the fullest extent. Having filtered the solution, 1 found that 

 only 60 parts of the crocus were dissolved, although when it 

 has been levigated, the tartar is capable of dissolving 75 instead, 

 of 60; consequently one-fifth of the tartar was uncombined 

 with oxide, and must vield a product intermixed with bitartrate 

 of potash. From repeated experiments, I am also of opinion 

 that a larger quantity of the crocus should be used than you 

 direct ; at least one-tenth more even when levigated. 



The process which I proposed in the examination of the Lon- 

 don Pharmacopoeia consisted in boiling antimony with sulphuric 

 acid so as to convert it into subsulphate, to wash this, and then 

 dissolve it in a solution of tartar. Now 1 prefer this process, be- 

 cause I find that it occupies scarcely two-thirds of the time re- 

 quired by yours. A very slight degree of washing is requisite; 

 the subsulphate of antimony is dissolved in a few minutes, instead 

 of requiring an hour's boiling, as you direct; the tartar being even 

 then imperfectly saturated : added to this, it is not requisite to 

 •dry the antimonial subsulphate, as you direct, with the 'sulphu- 

 retted oxide. "With respect to cost, I am at present uncertain ; 

 because 1 have not determined the exact quantity of sulphuretted 

 oxide yielded by certain proportions of nitre and sulphuret of 

 antimony ; but if you obtain nearly the whole of the antimony, 

 then, at the present price of nitre, your method is more econo- 

 mical as far as the first cost of materials is concerned ; but the 

 use of glass vessels, the long boiling, and the unnecessary dry- 

 ing of the oxide, all tend materially to diminish this advantage 

 of the cheapness of the first cost of the ingredients. 



Acelas lli/drargt/ri. — For preparing this compound, you 

 direct three parts of mercury to be dissolved in four ounces and 

 a half of dilute nitrous acid, or a little more than is required ; 

 and this solution is to be decomposed by one of acetate of potash. 



New Series, vol. ii. d 



