&S Os Chemical pAjaivalents. 



tialixe 42" of fluoric acid, 577 carbonic, 712 muriatic, 1000 

 suljjHuric, &;c, Eacli co!miin affv)rds also jiio.!;ressively increasing 

 ijiunbers. Those Kearest the top have the greatest aciJ or alka- 

 Jiue energies, as lueasured by their powers of saturation. The 

 ouliimn of Ricliter gives, therefore, as far as tlie analytical means 

 of hh time perniittcji, a table of tlie relative weights of what 

 has since !)een hvpothctically called ihe uloins. 



2. But tv»'-o cheujjcal constituents frequently unite in different 

 proportions, forming distinct and often dissimilar conipounds. 

 Thus, oxygen and azote constitute in one proportion, nitrous 

 oxide, tlie intoxicating gas of .Sir H. Davy; in a second propor- 

 tion, nitric oxide, the nitrous gas of Priestley; in a third pro- 

 portion, nitrous acid ; and in a fourth proportion, nitric acid. 

 Is there any law regulating these various compounds ; so that 

 knowing the first proportion, ive may infer the vviiole series? 

 Tills (juestion was first answered in a work containing many cu- 

 rious anticipations of discoveries, to which posterior writers have 

 laid claim; I mean Mr. Higi^ins's Comparative View of the 

 Phlogistic and Antiphlogistic Theory, printed in 17S8, and pub- 

 lished early in 17w!). Besides some additional facts, decisively 

 hostile to the hypothesis of phlogiston, this publication distinctly 

 advances the doctrine of multiple proportions, with regard to the 

 successive compounds of the same constituents. This was like- 

 wise interwoven, with new and ingenious views concerning gaseous 

 and atoniical combination. Mr. Higgins having felt himself ag- 

 grieved at seeing discoveries, clearly aimounced by him in 1789, 

 brought forward nineteen years afterwards by Mr. Dalton, in his 

 own name, published in 1S14 a book, entitled Experiments and 

 Observations on the Atonnc Theory and Electrical Phienomena. 

 In this work he gives numerous quotations from \\\i Comparative 

 l^ieiu, which abundantly establish his claim of priority to the dis- 

 covery of multiple proportions, and the atomic theory of che- 

 mistry. It is no fault of Mr. Higgins, that his first work par- 

 took of the imperfect analy.ses of the day. Indeed we have rea- 

 son, on the contrary, to be surprised at his rejection of many 

 errors then sanctioned bv high authority, and his promulgation 

 of many new trutl s, which might appear, to contemporary writers, 

 insulated, or of little consequence, but to which subsequent re- 

 searches have given a due place and importance in the system 

 of chemical knowledge. Who would deny to Columbus the 

 glorv of dibcovfjriiii; a new world, merely because the means of 

 research placed within his power, did not permit him to explore 

 its extensive coasts ? Is not that glory on the contrary greatly 

 enhanced, bv the very early period at which the discovery was 

 achieved, while navigation as a science was still unknown? i 



shall 



