3S ' . Anahjtkal ExpcrUnenis on 



distilled water ; but it slightly reddened litmus paper. It 

 produced no cloudiness in soKuions of muriate ot' barvtcs, 

 oi acctlte of lead, of nitrate of silver, or of sulphate of iron. 



The 39 jrrains of solid matter were dissolved in diluted 

 sulphuric acid, which left no residuum ; and the solution 

 was mixed with potash in sufficient quantity to cause the 

 aluminc at first precipitated again to dissolve. \\'hat re- 

 mained undi.^solvcd bv potash, after beiirg collected and 

 properly washed, was heated stroniilv and weighed ; its 

 quantity was 5 grain and quarter. It was white, caustic to 

 the taste, and had all the )iropcrties of lime. 



The solution was mixed with nitric acid till it became 

 sour. Solution of carbonate of ammonia was then poured 

 into it till the effect of decomposition ceased. The whole 

 tlirown into a filtratintr apparatus left solid matter, which, 

 when carefullv washed and dried at the heat of ignition, 

 weighed 06 grains. They were ])ure aluminc: hence the 

 general results ot the experin)ents, when calculated upon, 

 indicated for 100 parts of this specimen. 



Of alumine - ^ , 70 



Of lime - - , 1-1 



Of fluid - - - 2(3-2 



Loss - - - S-i 



The loss I am incliiied to attribute to sonic fluid remain- 

 ing in the stone after the process of distillation ; for I have 

 found, from several experiments, that a red heat is not suf- 

 ficient to expel all the matter capable of being volatilized, 

 and that the full effect can only be produced by a strong 

 white heat. 



Fiflv grains of a verv transparent part of the fossil, by 

 being exposed in a red heat for 13 minutes, lost 13 grains ; 

 but when they were heated to whiteness, the deficiency 

 amounted tu 15 grains j and the case was similar in other 

 trials. 



Different specimens of the fossil were examined \^'ith great 

 care, for the purpose of ascertaining whether anv mmiite 

 portion of fixed alkali existed in them ; but no indications 

 (»f this substance could be observed: the processes \\c\q. 

 conducted bv means of solution of the unaltered fossil iu 

 nitric acid ; the eaiths and oxides were precipitated from 

 the solution by being boiled with carbonate of aminonia ; 

 and after their separation the fluid was evaporated to dry- 

 ness, and the intrate of ammonia decomposed bv heat, when 

 no residuum occurred. 



A comparative analysis of 30 orains of a vcrv pellucid 

 specimen was made by solution iu lixivium of potash. This 



suecimea 



