i6 Inquiry into the Laws of Affinity. 



king the fame allowance of loo hours per year, it appears that it will require ribt lefs 

 than 598 years, to look with the 40-feet rcfleftor, charged with the abovementioned power, 

 only one fingle moment into each part of fpace ; and, even then, fo much of the fouthern 

 hemifphere \wlll remain unexplored, as will take up 213 years more to examine. 

 4 Slough, near Wind/or, June 20, 1799. 



III. 



Enquiries relative to the Latvs of Affinity. By Citizen BerthoLLET, Member of the 

 National Infitute, l^fc. Abridged by CiT. BoVItLOS LagrasgE.* 



X HE publication of the work of Cit. Bertholleton the affinities, has long been expedted 

 by chemifts. Their anxiety was doubtlefs very natural ; for an objeft fo important could 

 only be completed by that celebrated individual, whofe difcoveries have been fo highly 

 advantageous to focicty. 



The work here announced cannot be abridged without difficulty j for by prefenting the 

 reader with a mere analyfis of each article, much information would be loft. Hence we 

 fliall frequently fuffer the author to fpeak for himfelf, as his work is a coUeflion of fafts, 

 upon which the theory is eftablifhed. 



Cit. Berthollet has divided his memoir Into fifteen articles : 



In the firft of thefe, the author makes a panegyric upon Bergmann, who devoted his 

 attention to this fubje£t with the greateft fuccefs. Cit. Berthollet has principally attended 

 to the work of the Swedilh chemift, when treating on this fubje£l:. He then ftates the 

 objeft of his memoir : *' It is my intention" fays he " to prove that the ele£live affinities 

 do not aft like abfolute forces, by which one fubftance might be difplaced by another in a"^ 

 combination ; but that in all the compofitions and decompofitions which are owing to 

 ele£live affinity, a divifion is made of the obje£t of the combination between the fubftances 

 whofe actions arc oppofed ; and that the proportions of this divifion are determined not 

 only by the energies of affinity of thefe fubflances, but alfo by the quantity with which 

 they a£l ; fo that the quantity may compenfate for a want of the affinity, and produce a 

 fimilar degree of faturation. 



If, continues the author, I eftablifh that the quantity of a fubftance can fupply the want 

 of force of its affinity, it will follow that its a£tion will be proportionate to the quantity 

 nccelTary to produce a determinate degree of faturation. I denominate mafs, that quantity 

 which is the meafure of the capacity of the faturation of different fubftances. 



When therefore I compare the affinities of fubftances, I fhall direft my attention to tht 

 ponderable quantity, which in this comparifon ought to be equal ; but, when I compare 



* Annales de Chimie, XXXVI. 30Z. 

 r - their 



