102 Canadian Record of Science. 



temperature that will drive off a portion of the water of 

 combination, there results a substance so brittle that it may- 

 be readily crumbled between the fingers. Wherever asbestus 

 is found in rock that is faulted and shattered, the fibre is 

 almost certain to be harsh at or near the surface, although 

 at greater depth softer fibre may be found. 



If the aqueous orgin of asbestus be admitted, it seems 

 reasonable to suppose that all the fibre when first deposited 

 was soft and flexible, containing a maximum amount of 

 water, and that movements of the rock producing heat have 

 driven off a portion of the water of the contained asbestus 

 and thereby destroyed the softness of the original fibre. 

 Yeins at considerable depths may have been subjected to 

 the heat produced by these movements and yet not deprived 

 of any portion of their original water, because of the resist- 

 ance of overlying rocks. 



It is probable, too, that movements of the rocks and 

 resulting heat have been intimately connected with the 

 formation of picrolite, 1 a " columnar variet}^ of serpentine, 

 with fibres or columns not easily separable." In all the 

 asbestus mines picrolite is found along the lines of faulting, 

 and at one point near Broughton Station on the Quebec 

 Central Eailway, where there is abundant evidence of faults, 

 picrolite abounds. Here mining was formerly carried on 

 and large quantities of rock have been removed. Hundreds 

 of tons of picrolite of most fantastic forms constitute one of 

 the dumps, the whole forming a remarkable sight. 



Associated with the chrysotile are found some singular 

 forms of serpentine. At the Megantic mine, Coleraine, there 

 occur narrow seams of material so soft that it may be com- 

 pressed between thumb and finger, and varying in color 

 through white, blue, green and yellow ; when exposed to the 

 air it gradually becomes hard and assumes a waxy lustre. 

 Dr. B J. Harrington has already referred to the green 

 variety, and his analysis shews it to be simply a variety of 

 serpentine. 



1 Dr. Hunt gives 12.45 as the percentage of water in a picrolite 

 from Bolton, Quebec Geo. Survey Report, 1863, p. 499. 



