OF ZIXC AND ANTIMONY. 371 



different processes, it will be noticed that they seldom perfectly agree ; so that, whatever 

 view may be taken of the subject, it will now become a matter of the highest impor- 

 tance to ascertain how far, if at all, the determinations of the chemical equivalents have 

 been influenced by similar causes to those which have produced the variations described 

 in this memoir. This influence can only be detected by multiplying the determinations 

 by as many different processes as possible, and submitting the results to a rigorous 

 mathematical scrutiny. 



If the doctrine of this memoir is correct, and the chemical equivalents are really 

 liable to variation, it will have an important influence on chemical philosophy. The 

 atomic theory, as at present interpreted by chemists, is irreconcilable with it, and our 

 present ideas in regard to isomorphism must be materially changed. But it must be 

 remembered, that the conclusions of the memoir are drawn from the examination of 

 only two compounds, and therefore that it would be premature to dwell on these ob- 

 vious consequences of the principle until it has been substantiated by further investiga- 

 tions. In conclusion, I would express my obligation to the gentlemen who have 

 assisted me in the labor of the investigation, which, on account of the large number of 

 analyses, has been very great, and could not have been concluded so soon had it not 

 been for their A'ery great industry and zeal. 



Cambridge, July 20th, 1855, 



