On the Laws of Affinity. 1 9/ 



quantity of water difcharged, &c. I have given it fair trial 5 

 from which 1 have no hefitation in faying, that (hould an 

 occafion of real danger from fire unhappily arife, it is my 

 opinion the patent pump might be of the greateft utility/' 



XXXI. Refearcbes re/peeling the Laws of Affinity. ^ By 

 C. Berthollet, Member of the French National 

 InJUtute. 



[Continued from p. 142.] 



On the Influence of the Proportions in Complex Affinities. 



,1 



M my refearches on the laws of affinity I have afcertained 

 the principal relults prefentcd by complex affinity, when the* 

 force of coheiion or that of elalticity is fufficiently ftrong to 

 produce that change of bale which has been afcribed to the 

 fuperiority of the divellent affinities over the quiefcent affi- 

 nities. But I avoided entering into the nceeiTarv details for 

 determining the changes which may arife from different 

 portions of the fubitances brought into ad 10m when the f rce 

 of coheiion is not fufficiently great to caufe the effects of this 

 difference to diiappear. I promiled (Art. XII. No 6.) to 

 return to this f abject, which I fhal! now proceed to do. 



According to rhe theory explained (Art. V. No. 5.), all 

 fubftances exert a mutual action while they are in the liquid 

 ftate; f> that in a folution, for example, of fulphate of potafh 

 and muriate of foda, theie two fails are not diltinct, while 

 there is no caufe to determine the reparation of their com- 

 bination ; but there exiii in this liquid fulphuric acid, mu- 

 riatic acid, foda, and potafh. I (hail, however, continue to 

 make ufe of the ordinary language, which after this notice 

 can produce no ambiguity. 



2. 1 begin with mixtures in which aconfklerableforceofcry- 

 utilization muftdetermine the combinations which are formed. 



Experiment A. Equal parts of nitrate of lime and fulphate 

 of potafh were mixed : after the feparation of the fulphate of 

 lime firft formed, the liquid, by fucceffive evaporations, 

 yielded only nitrate of potafh and fulphate of lime. After 

 the laft evaporation, however, fome cryftals of fulphate of 

 potafh were procured*; * there remained only a very fmall 

 quantity of uncrvftallizable liquid, which precipitated with 

 carbonate of foda and with nitrate of barytes; fo that it con- 

 lifted of a little fulphuric acid and lime, and very probably a 

 larger portion of nitrate of potafh. 



The quantity of fulphate of lime which was depofited in 

 N 3 the 



