SCIENTIFIC KEWS. 223 



fjiB^ wf(h tlie former, all founds feem more grave : with the 4- pole makes 

 '-"-.-ore acute. r*t"j!„a, 



In general the two poTes of the pile produce oppofitethe — , blue, 

 efTeds. Jj^^^'j' ^""^ "a- 



Such are the refults of Mr. Ritter's experiments." We have + gives an acid 

 no opportunity of verifying their accuracy; but their fingu- ^^^' akaline. 

 larlty, their number, and particularly the ingenuity of their founds, 

 author, lead us to prefume, that this account of them will "~ ''g'^'^ns 

 be read with pleafure. Thrtwo pole* 



SOCIETE PHILOMATH, f "^rally pro- 



duce oppoute 

 effcds. 



Ahfirad of fome Remarks on the Acetile of Lead, by 

 Cit. Thenard *. 



A MANUFACTURER of acetite of lead was obliged to A manufaaurer 

 flop his works, beingr no longer able to make the fait crvf- ?!'''S^^5°*°P 



iiis woric be— 



tallize in needles, but always obtaining it in laminae, which caufe his'acetite 



induced purchafers to refufe it; Cit. Thenard inquired into o^'^-*.^ was al- 



the caufe of this phenomenon, and ioon perceived, that it formsof lamlnjc, 



was owing to the proportions of the conftituent principles 



of the fait. He fucceeded in forming a fait perfedly fimilar 



to it, by boiling in water a hundred parts of the acetite of 



lead of the fliops, with a hundred and fifty parts of litharge 



well dried, and deprived of carbonic acid by means of fire, 



Analylis corroborated the exiftence of two fpecies of acetite Two fpec'es of 



©f lead; one, long known, confifts of oxide of lead o.58, ^'^^^^''^*"'^- 



acetous acid 0.26, and water 0.16, the other, which has 



hitherto efcaped the notice of chemifts, contains oxide of 



lead 0.78, acetous acid, 0.17, water 0.05. 



The former of thefe falts has an excefs of acid, and a ftrongly The common or 

 faccharine tafte; cryftallizes in needly prifms, "which appear ^^^^'^p]^'^'^^''" ' 

 to be hexagonal, and terminated by hexaedral pyramids ; 

 undergoes no alteration in the air; is very foluble in water, 

 and forms with it a folution feebly precipitable by carbonic 

 acid. The latter, on the contrary, is neutral ; has a lefs per- The newer 

 ceptible faccharine tafle ; afFeds a lamellated figure ; is foluble 

 in vinegar, and then exhibits on evaporation the neediy form ; 



. * Bulletin des Sciences, No. 77. 



efflorefces 



