156 



Analyfis of 80 



grains. 



1. Expofurc to 



# 



Water came 

 over. 

 19 grains 



itry (lightly 

 acid. 



2. Solution of 

 the refidue in 

 fulph, acid : 

 precipitation and 

 re-folutjon by 

 alkali. Onp 

 grain and a quar- 

 ter of lime re- 

 mained undif- 

 folved. 



3. 'Kitnc acid 

 was added, in ex- 

 ccfs, and then 

 carbonate of am- 



Mlt. DAVYS EXPERIMENTS 



of ammonia, and gave a light yellow precipitate by expofare 

 to ammonia ; but after this, when neutralized, it did not afre<5t 

 prufTiate of potafli and iron, fo that its colouring matter, as 

 there is every reafon to believe, was oxide of iron. 



IV. Analyfis of the FoJiL 



Eighty grains of the foffil confining of the whiteft and moft 

 tranfparent parts that could be obtained, were introduced into 

 a fmall glafs tube having a bulb of fufficient capacity to receive 

 them with great eafe. To the end of this tube, a fmall glafs 

 globe attached to another tube, communicating with a pneuma- 

 tic mercurial apparatus, was joined by fufion by means of the 

 blow-pipe. 



The bulb of the tube was expofed to the heat of an Argand 

 lamp ; and the globe was preferved cool by being placed in a 

 vetfel of cold wat^r. In confequence of this arrangement, the 

 fluid difengaged by the heat, became condenfed, and noelafiic 

 matter could be loft. The procefs was continued for half an 

 hour, vvhent the glafs tube was quite red. 



A very minute portion only of permanently elaftic fluid 

 pafled into the pneumatic apparatus, and when examined, it 

 proved to be common air. The quantity of clear fluid colle6ted, 

 when poured into another vefl'el, weighed 19 grains, hut when 

 the interior of the apparatus had been carefully||viped and dried 

 the whole lofs indicated was 21 grains. The li) grains of fluid 

 had a faint fmell, (imilar to that of burning peat ; it was tranf.» 

 parent, and tafled like diftilled water : but it flightly reddened 

 litmus gaper. It produced no cloudlnefs in foliitions of muriate 

 of baryfes, of acetite lead, of nitrate of filver, or of fulphate 

 of iron. 



The 59 grains of folid matter were diflblved in diluted ful- 

 phuric acid, which left, no refidupm ; and the folution was 

 mixed with potafh, in fufficient quantity to caufe the alumine 

 at firii precipitated again to ditfolve. What remained un- 

 ditfolved by potath, after being collected and properly waihed, 

 was heated flrongly and vs'eighed ; its quantity vvas a grain 

 and quarter. It was white, cauftic to the laitej, and had all 

 the properties of lime. 



The folution was mixed with nitric acid till it became four. 

 Solution of carbonate of ammonia vyas then poured into it till 

 the effedt of decompofition ceafed. The whole thrown into a 



filtrating 



