210 On Metallic Sulphureis. 



without decomposing it. Is this then a simple solution of 

 sulphur in copper? No one will suppose it. 



'* He pretends that a dose of sulphur invariably fixed by 

 nature, attaches itself to antimony, and that man can nei- 

 ther increase nor diminish it. He lixes this proportion at 

 25 per cent." 



It is not I, but nature, or whatever power you will, 

 which places a barrier between it and the efforts of every 

 chemist who might propose to make sulphuret of antimony 

 beyond or within this proportion : I have not therefore 

 assigned it any law of my invention; I have only verified 

 it. I have followed this precept, which Berthollet himself 

 traces out to us in his profound work. When a substance, 

 therefore, says he, combines with another, we must deter- 

 mine the proportions, examine the properties. Sec* Such 

 indeed has been the constant object of the eflfbrts of che- 

 mists since the time when they found that this determina- 

 tion was one of the most important bases of the history of 

 combinations, and of the science of analysis. No one, 

 however, will doubt, that nature cannot abandon her com- 

 pounds to the chance of the variable proportions, which 

 Berthollet has chosen as the basis of his system ; but it is 

 no less true, that in proportion as the sphere of sulphurets 

 extends, we do not see that the new facts which each day 

 accumulates are of a nature to strengthen it. 



" He has however found sulphurets of antimony which 

 had an excess of sulphur. Sulphurets of copper, of lead^ 

 &c., are also found mixed with a like excess." But if it 

 can be taken away without changing their appearance, with- 

 out taking any thing from the characters aiid (pialities 

 which distinguish these sulphurets, I shall say that this 

 sulphur is foreign to them. The same thing cannot be 

 said of a pyrites, from which has been taken the sul- 

 phur, which makes the difference between sulphuret at a 

 minimum, and that at a maximzim. That there should be 

 sulphur mixed with sulphurets, without making part of 

 their constitution, is not surprising. We see it every day 

 mixed in the same manner with argil^ alum, stilphatc of 

 lime, See. 



" He has combined oxide of antimony with diffcrenf 

 proportions of sulphuret, and he had mixtures which may 

 be represented bv this formula: oxide + 1 + 2 + 3, &c. 

 of sulphuret of antimony : Has it not thereby formed real 

 combination?? 8-;c." 



I shall replv to ihi^, that solutions begun, or which have 



not 



