ON A.WNERAL FRPM BEVONSHIRE. 153f 



filtrating apparatus left folid rpatter, which when carefully ^onh. The 

 vvalhed and dried. at the heat of ignition, weighed 56 grains, mtnel' zft^r'-ig^ 

 They were pure alumine: hence the general refults of the nition, was 56 

 experiments, when calculated upon, indicated for 100 parts of ^'^^'"^* 

 (iiis fpecimen. 



Of alumine 

 ■ Cff lime 

 Of fluid : 

 Lofs 



The lofs I arn inclined to attribute to (brae fluid remaining The lofs appears 

 in the flone after the procefs of dilHlIation ; for I have found, volatilizablcT 

 ^rom feveral experiments, that a red heat is not fuificient to matter, 

 expel all the matter capable of being volatilized, and that the 

 full effect can only be produced by a llrong white heal. 



Fifty grains of a very tranfparent part of th^ foflil, by being 

 expofed in a red heat for iifteen minutes, lo(| 13 grains; but 

 when they were heated to whitenefs, ihe deficiency amounted 

 to 15 grains, and the cafe was fimilar in other trials. 



DiflTerent fpecimens of the foHTil were examined with great The mineral 

 care, for the purpofe of afcertaining whether any minute por- f^^.^^'"* "° * " 

 tion of fixed alkali exifled in them ; but no indications of this 

 fubflance could be obferved ; the proceflfes were condufled 

 by means of folution of the unaltered foflil in nitric acid; the 

 earths and oxida| were precipit^||d from the folution by being u^ 



boiled with carbonate of ammorfl^ and after their feparation, 

 the fluid was evaporated to drynefs, and the nitrate of ammonia 

 decompofed by heat, when no refiduum occurred, 



A comparative analyfis of 30 grains of a very pellucid fpecl- Other analyfes. 

 men was made by folution in lixivium of potafli. This fpeci- 

 men loll 8 grains by long-continued ignition, after which it 

 eafily dilfolved in the lixivium by heat, leaving a refiduum of 

 a quarter of a grain only,' which was red oxide of iron. The 

 precipitate from the folution of potalh, made by means of 

 muriate of ammonia, weighed, when properly treated, 21 

 grain5^. 



Several fpecimens were diftilled In the manner above d^- 

 fcribed, and in all cafes the water colleded had fimilar proper, 

 ties. The only teft by which the prefence of acid matter, in % 

 it could be detected, was litmus paper; and in fome cafes the 

 efFed upon this fubflance was barely perceptible. 



V. Gaieral 



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