gt Inquiry into the Laws of /ffintiy, 



, What has given credit to Pinchbeck as the inventor of a watch thermometer, muft have 



been the circumflance of his purchafing from Berthoud, when in London, I766> 



for his prefent Majefty, a watch with center feconds, the common Verge Efcapement, 



and having a thermometej-, or compenfation piece, which Berthoud fays, was the firft 



pocket watch made with fuch a thing. Kendal copied this compenfation work in fome 



watches that he made afterwards. 



Sully wrote his Regie Artificielle in 1717, and J. Le Roy gave an edition of it in 



1737. He was an Englifli watch maker; what time he went to France I know not, but 



he was a great genius, much efteemed there, and had the merit of putting the bufinefs in 



a better train, reared up workmen, and gave them quite new methods. Julien Le Roy 



thought highly of him, and was himfelf a man of very uncommon ability. 



Excufe this defultory manner, a little trouble may make it more connected. 



T. R. 



V. 



Inquiries relative to the Laws of Jffinitys hy CiT. BertholLET, Memher of the Nationa! 



Injiitute of Arts and Sciences *. 



(Concluded from page 21. J 

 ARTICLE X. 



On the Determination of the EleBive Affinities. 



-To 



determine the eleftlvc afHnity of two fubftances for a third, according to the notion 

 which we ought to conceive of it, confifts in afcertaining in what proportion the third fub- 

 ftance divides its a£lion between the two firft, and to what degree of faturation each of 

 thefe muft arrive when their forces are equally oppofed. The relative affinity will be in 

 proportion to the degree of faturation they would attain, on account of the quantity which 

 fiiall have a£ted ; fo that if the quantities were equal, the comparative degrees of faturation 

 would afford the raeafure of the refpe£tive affinities. 



2. When I fpeak of the faturation of a fubftance, I do not mean that abfolut.e faturation 

 in which all reciprocal a£tion would ceafe, but a degree of faturation which is eafily diftin- 

 guifhed, and is common to all combinations. It is that of neutralifiition, in which none of 

 the properties of the conftituent parts predominate. The term of cryftallifation of falts, 

 does not always coincide with that of neutralifation j for example, with refpeft to the car- 

 bonates of alkali, which ftill continue to afford indications of alkalinity, and with the aci- 

 dulous tartrite of pot-afh, which on the contrary retains an excefs of acid. Neverthelefs, 

 we may take the laft combination at the term in which it is neuter, becaufe it ftill poffeffea 



• Tranflated from the Annales de Chimie, XXXVII, 151. 



•■ the 



