158 ^R« daw's EXFERIMENT'd. 



V. General Ohfcrvations, 



The acid matter I Have made feveral experiments with the hope of afcer- 

 mthe water was Gaining the nature of the acid matter in the water: but from 



not nitric, mur. ,, . /ri-i-, r • /- i i i . r , 



©r fulph. I"® impolliDinty ot procuring any conuderable quantity of the 



foffil, they have been wholly unfuccefsful. It is, however, 

 evident, from the experiments already detailed, that it is not 

 one of the known mineral acids. 



It is foreign to [ am difpofed to believe, from the minutenefs of its propor- 

 tion, and from the difference of this proportion in different 

 cafes, that it is not effential to the compofition of the ftone; 

 and that, as well as (he oxide of manganefe, that of iron, 

 and the lime it is only an accidental ingredient, and on this 

 idea the pure matter of the foffil muft be confidered as a che- 

 mical combination of about thirty parts oftvater and feventy of 

 a I amine » ^ ^^^ 



Aluminc has an The experimiiits of M. Theodore de Sauffure on the pre- 



affimtyfor cipitation * of aluraine from its folutlons, have demonflrated 



^ the affinity of this body for water ; but as yet I believe no 



aluminous flone, except that which I have jufl defcribed, has 



been found, containing fo "large a proportion of water, as 



thirty parts in the hundred. 



Diafpore exim. The diaspore, which has been examined by M. Vauquelin, 



y auquein, ^^^^ which loles tixtcen or feventeen parts in the hundred by 

 contains 80 am- ... ' ^^ ^ 



mine and j6 ignition, and which contain|ijtearly eighty of jjpimine, and only 



^'^^^^' three of oxide of iron, is fuppofed by that excellent chemift to 



be a compound of aiamine and water. Its phyfical and che- 

 mical characters differ however very much from thofe of the/ 

 new m/^t and other refearches are wanting to afcertain whe- 

 ther the part of it volatilized by heat is of the fame kind. 

 Cornifh mineral I have examined a foffil from near St. Auftle, in Cornwall, 

 refembling the y^yy timilar to the foffil ffom Barnftaple in ali lis gmeral vht- -m 

 papgr^ mical chiiraBers; and % have beepjnformed, thai an analytis 



of ht, made by the Rev, William Gregor fome months fmce, 

 proves that it confifls of fimilar ingredients. 

 Propofcd names. Dr. Babington has propofed to call the foffil from Devon- 

 fliire Wavellite, (rom Dr/Wavell^lhe gentleman whodifcovered 

 it 5 but if a name founded upon its chemical compofition be 

 <? preferred, it may be denominated JJydrargillite, from ilx!^ 

 water, ar^^ a|yi?vXcj clay. 



* Journal de Phyfique, Tom. LIT. p. 2S0. 



On 



