36 ^^ 'f'f^' 



e- fttaw hr>6p wBi<i^ sfefves i6 ftitWi fh^ hffip. 

 h. Afro.Wfe attacb^cl t6 the brass hftop. 



f. Ciif) that receives thfc oil which nia^^ fall SfoM tl* 



cylihdfts. 

 /■. Cf\s>al jj&ndatrts a!fa6!i*rd td fft« bfifS hfldj^. - ■ ^ ^ • ■•'■ 

 /. Ho.op of wBitft crnpft attached to tft« loWef edge drtfH 



bni55 hoop immediately behind the p«ndants. 

 »?. Refiectof of ^hite crape, v/hich rests on thft tufeeS e. 

 l^ig. o.'-^^-ti a larger scale.. 



g. %ttX\bii of th^ brass stopper with the small screw ift its 



axis : the screw is Represented as 6pen to give ad- 



rnissidn to the air int6 the reservoir. ■ 

 h. Collar of leather which, when the Screw i$ 6l6§e^, 



presses upon <r, and excludes the air of the attriosphcire 



fioni the reservoir. 

 a. S(tctioh of a part of th^ hollow hoop which serves as 



a reservoir for thtf oil. 



IV. 



Ysds fexsards i JJisfory of Tin. Bj/ Professor Proost.* 



^-jp, Tin and Muriate of Atnhionia. 



Facts and ob- -^ ^^^ muriate when heated with granulated tin yielded the- 

 «-;;-v.,rions on following results :— 

 tin •i;il its , . , . . . . 



co3j««nds. When the heat is on the p)oint ot evaporating mt muriate, 



the tin acts upon the water of this salt, and decomposes it. 

 'J'iie metal Seizes its oxigen, and causes a disengagement of 

 inflammable gas. One hundred ounces of muriate afford from 

 eleven to twelve inches of gas : they may perhaps afford more; 

 bnt tlse retort generally bursts before the opefatioa. is com- 

 pleted. This hydrogen has nothing in it remarkable. 



At the close of the operation, a saline mass js found, com^- 

 posed of muriates of tm and ammonia, and of the granulated 

 tin. The oxide of this muriate is only at the minimum; for 

 it gives a purple colour with gold, and hjack with hydro- 

 euiphurated water, Src. If tin be merely boiled in a solutloij 

 of 9d\ ii.mrr>oniac, a considerable portipn will be dis5(a|vc<l. 



