32 
~waters of Jakes and rivers throughout Canada. It was intended to 
publish this valuable Shnielnnien to the labors of the Club, but Dr. 
Kemp prefers to withhold it until, with an instrument ne greater 
power, he has made more extended observations of the phenomena 
witnessed by him. 
‘¢ Aspgstos :” W. P. Anperson, C.F. 
The paper was prefaced by an expression of regret that, in a district 
so rich in minerals and fossils as Ottawa, more serious attention was 
not bestowed upon the geological branch of Natural History, and a hope 
that the defect would be remedied to some extent during the coming 
season. 
% % % % * * * 
Asbestos is aterm used to denote a peculiar form assumed by several 
minerals, rather than to designate any particular species. ‘Tremolite, actinolite, 
and other forms of hornblende containing little alumina, augite and serpentine, 
pass into fibrous varieties, all of which are popularly known as asbestos, though, 
technically, that name is restricted to the hornblende variety, while fibrous 
serpentine shoul 1 be called chrysotile. 
All these varieties are similar in appearance, the fibres, which run trans- 
versely of the veins and parallel to each other, looking, when compact, like 
mica. The color varies from pure white to gray, or greenish, and the texture of 
the separated fibres from that of coarse cotton to the finest silk. The longest 
fibre of which mention has been found came from Italy, and measured 44 
inches. In Canada it is never found of any great length, the average being 
probably not over1} inches. The fibre has a soft, greasy feel. Specific gravity 
varies from 2-9 to 3-4. Before the blowpipe a single fibre fuses into a white glass 
globule, specimens containing most iron being most readily fusible. In 
masses it is infusible at ordinary temperatures. ‘This property, together with 
its insolubility in acids, its being a bad conductor of heat, and the remarkable 
strength of its fibre, are qualities that make it valuable in several branches of 
manufacture. 
To understand its chemical character it will be necessary to give sone 
account of the rocks in which it exists. 
In the lower members of the oldest groups of rocks, three minerals, horn- 
lende, augite, and serpentine, are more or less widely distributed. 
Hornblende consists of silica and magnesia, with a greater or less quantity 
of lime, protoxide of iron, and other oxides, and is usually found ina scaly 
form. 
Augite differs from hornblende mainly in the shape of its crystals, and in 
containing, usually, a greater portion of lime and less magnesia. 
Serpentine contains little or no lime, but has about 12 per cent. of water in 
its composition, in addition to the ingredients of hornblende. 
All these substances are classed under the same head mineralogically—being 
non-aluminous silicates—and are, indeed, so closely connected that it is some- 
times difficult for even the mineralogist to tell to which species a specimen 
should be referred. 
Another fact that shews the close relation hornblende, augite and serpen- 
tine bear to one another is that, amongst themselves, they are frequently subject 
to pseudomorphism, a process by which the chemical character of a mineral is 
changed while it retains its original form of crystalization, ‘There is no doubt 
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