o viineral Production from Devonshire. 37 



glucine or ittria ; and its perfect solubility without residuum 

 m alkaline lixivia showed that it was aluminc. 



When the opake varieties of the fossil were fully ex- 

 posed to the agency of alkaline lixivia, the residuum never 

 amounted to more than l-20lh part of the weight of the 

 whole. In the w^hite opake variety it was merely calca- 

 reous earth ; for, when dissolved in muriatic acid, not in 

 excess, it gave a white precipitate when mixed with solu- 

 tion of oxalate of ammonia, and did not affect solution of 

 prussiale of potash and iron. 



In the ffreen opake variety calcareous earth w^as indicated 

 by solution of oxalate of ammonia : and it contained oxide 

 of manganese ; for it was not precipitated by solution of 

 ammonra; but was rendered turbid, and of a gray colour, 

 bv solution of prussiate of potash and iron. 



The residuum of the alkaline solution of the yellow va- 

 riety, when dissolved in muriatic acid, produced a small 

 quantity of white solid matter when mixed with the solu- 

 tion of the oxalate of ammonia, and gave a light yellow 

 precipitate bv exposure to ammonia; but after this, when 

 neutralized, it did not affect prussiate of potash and iron, 

 so that its colouring matter, as there is every reason to be- 

 lieve, was oxide of iron. 



IV. Analysis of the Fossil. 



EiMity grains of the fossil, consisting of the whitest and 

 most transparent parts that could be obtained, w-ere intro- 

 duced into a small glass tube having a bulb of sufficient 

 capacity to receive them with great ease. To the end of 

 this tube a small glass globe, attached to another tube com- 

 municating with a pneumatic mercurial apparatus, was joined 

 bv fusion by means of the blow-pipe. 



The bulb of the tube was exposed to the heat of an Ar- 

 gand lamp, and the globe was preserved cool by being placed 

 in a vessel of cold water. In consequence of this arrange- 

 ment, the fluid disengaged by the heat became condensed, 

 and no elastic matter could be lost. The process was con- 

 tinued for half an hour, when the glass tube was quite red. 



A very minute portion only of permanently elastic fluid 

 passed into the pneumatic apparatus, and when examined 

 it proved to be common air. The quantity of clear fluid 

 collected, when poured into another vessel, weighed I9 

 grains; but, wiien the interior of the apparatus had been 

 carefully wiped and dried, the whole loss indicated was 21 

 grains. The ly grains (jf fluid had a faint smell, similar to 

 llut of burning peat; it was transparent, and tasted like 

 C 3 distilled 



