On the Laws of Affinity* f 20 



they can procure, under a pretence of repairing their loll 

 ftrength. We are told the fame thing by captain Woods 

 Rogers, who fays that the Brazilian women, at the time of 

 their delivery, go out alone into the Woods, and when deli- 

 vered warn the child ; while the men place thefnfelves in 

 bed for twenty-four hours, where they are attended in the 

 fame manner as if really fuffering from the pains of labour. 



Lafitau denies that the men indulge themielves on this 

 occafion, and is of opinion that this practice is a religiou3 

 ceremony, which muft be performed for fix months with the 

 ftricteft falling, and other acts of mortification aimoft infup- 

 portable ; and that it ought to be confidered as a kind of pe- 

 nance for the fin of our firft parents. If this be true, the* 

 notion of original fin muft be difTufed throughout the whole 

 world, and have been conveyed from the old to the new con- 

 tinent : but this I mail not here examine. He, however^ 

 agrees with Labat in faying that this drift fading is obferved 

 only in regard to the firfi-born child; but, inftead of fix 

 months, as above mentioned, Labat makes the duration of 

 it to be only thirty or forty days. 



[To be continued.] 



XXI. Refearches refpecli?ig the Laws of Affinity. By 

 C. Berthollet, Member of the French National 

 Injlitute. 



[Continued from p. 74.] 



XIII. On the Precipitation of Metallic Solutions ly other Metals «, 



t. VV HEN metals are precipitated by fubftances which 

 do not feize upon their oxvgen, the precipitates retain a por- 

 tion of the acid, and often lome of the precipitant. Of this 

 we have a ftriking inftance in the precipitate of the oxygen- 

 ated muriate of mercury by the alkalis and lime. Ort 

 expofing the precipitate to a fuflficient heat, one portion of" 

 mercury, more or lefs confiderable, according to the nature 

 of the precipitate^ is reduced, another is fublimed, and forms 

 a muriate, not merely becaufe the muriatic acid is combined 

 with a portion of the oxide of mercury, as I fuppofed, (Me- 

 moirs of the Academy ,) but becaufe the expanfive force of the 

 heat, and the tendency to the combination of the muriatic 

 acid, acting upon the oxide of mercury, caufe, as we may 

 fay, a new partition of it to be made : the precipitate by am- 

 monia retains a portion of the ammonia) the precipitate of 

 Vol, X, I the 



