new Varieties of Vermiculites, 139 



I. 



0) (2) 



Loss at 100° C. . . . 575\ „19 



„ about 300° C. \ 10-97 J * ^ 



„ red heat . . J .. 8*60 



16-72 16-72 



II. 



(1) (2) (3) Mean. 



Loss at about 300°. ~] -, , ^ f"2-54~] ,-, ~, 



„ red heat . }^65 | 9 . 13 | 1171 



11-65 11-67 11-71 11-68 



Table III. gives the percentages of water found in air-dried 

 specimens of the Pelham vermiculite ; and Table IV. gives the 

 percentages of water found in the same specimens dried at 100° C. 



III. 



(1) (2) (3) (4) 



Loss at 100° C. . 10-83 10-72 . . 10*80 

 „ about 300° C. 4-35" 



,-35\. 

 »-65J 



20-83 20-99 .. 20-94 



IV. 



(1) (2) (3) (4) Mean. 



Loss at about 300° . 4-901 n . B0 n . 13 n . 43 

 „ red heat . 6'31 J 



TT^l 11-50 11-13 11-43 11-32 



The marked hygroscopic character of the Culsagee, Lerni, 

 and Pelham vermiculites led to the idea that the discrepancies 

 between the published analyses of Jefferisite and Hallite might 

 be due to the hygroscopic nature of these minerals. The water 

 contained in each of them was therefore carefully again deter- 

 mined. Table V. gives the percentages of water found in air- 

 dried specimens of Jefferisite; analyses (1), (2), and (4) of 

 Table VI. give the percentages of water found in the same spe- 

 cimens dried at 100°; (3a) gives the percentages of water found 

 in the mineral dried for three months over sulphuric acid, and 

 (3b) the percentages found in the same specimen subsequently 

 dried at 100° C. 



