On the Affinity of Earths for each other. 341 



• 4. Twenty feries in a battery of this kind produce fenfible 

 but feeble fliocks, and when a fingle metallic feries with a 

 gold wire and two glafles of water is fubftituted for one of the 

 primary feries, hvdrogeii is given out by the metallic point 

 in the gUifs of water in the place of the acid, wiiilft oxygen 

 is evolved from the point in the other glafs. 



5. In the galvanic batteries with charcoal, fulphuric acid 

 may be fiibftituted for nitric acid; and folution of fulphuret 

 of potafli for the water, without any material alteration in 

 the nature of the agency; the folution of the fulphuret in- 

 deed, feems, in fonie meafure, to increafe its iiitenfity, and 

 combinations containing this fubftance, denfe charcoal, and 

 concentrated nitric acid, appear to be fuperior in a6tivitv to 

 fimilar combinations containing copper, and the fame fluid 

 elements, and to be nearly equal to thofe compofed of zinc, 

 lilver, and water. 



January g, 1802. 



LV. Ohfervat'tons on the Affn'itv ivh'ich Earths have for each 

 other. By DARiiAca, Pufil o/* VAuaUELIN, and his 

 Affijlant in the School of Mines *. 



X H E analyfis of ftones has long engaged the attention of 

 chemills. The moderns, aflifted by more correal inflruriients, 

 have carried this branch of cheraiftry to fuch a decree of 

 perfection, as feems to leave nothing more to be defirea ; but 

 C. Guyton, in a memoir, in which he treats with minutenefs 

 on the different affinities which the earths exercife on each 

 other, relates fcvcral obfervations, printed in the 37th number 

 oi ihe Annales i{e Chimie, which excite great doubt in regard to 

 the exaftnefs of the analyfes hitherto made, and which invite 

 all cheinifts to be on their guard, lell they fljould take a fimple 

 earth for a mixture of feveral. The embarraflTment which 

 thefe afuuiiits daily gave rife to, determined me to examine, 

 with great care, ihe ditferent circumllances under which thev 

 may take place ; for, if it is of importance to point out thele 

 new combinations, it is no lefs lb to reduce them to their 

 ju(l value. 



Jlx/>. I. C. Guyton having mixed ten centilitres of lime 

 water with two centilitres ot barytes water, there were fooix 

 formed white clouds, which united, and depodted themfelves 

 il iht bottom of the vclfel containing the mixture. In con- 



• From ihc Anna. ''•I e/e C6mU, No. iib. 



Y 3 fequence 



