A very interesting phenomenon may be noticed at some of the mines in connection with this contorted matter. It is the transposition of the serpentine into Asbestos fibre, by the action of the atmosphere. This is to be seen on the dumps where the filling matter and cobbed rock is exposed. In one or two cases I have seen large quantities of broken rock changed into fibre after a few years, by atmospherical chemical agencies. In so many cases I find people are prejudiced from going deeper than a few feet from the surface, as not finding a copious supply of Asbestos there, when _good_ indications are shown they become disheartened. Therefore, from these practical facts it will be seen that in order to get the best results it is necessary to work at the lowest possible level when a favourable out-crop is shown, as, possibly, working at a high elevation on the out-crop may be a mistake, where a lower point is available. There are good indications of Asbestos where the serpentine is crossed by quartzose, gneiss, or "traverse dykes," and some valuable finds have been made at the junction with the dioretic rocks. When the serpentine is found dark in colour, to have a granular appearance, containing many dark grains of, perhaps, felspathic crystals, the Asbestos will be of a dark, dull, translucent lustre, very compact, and easily fluffed to a fine silken fibre. The admixtures of hard and soft serpentine, where not effected by a fault, may sometimes be regarded as a doubtful indication of an immediate find, but if its hardness increases on descending, and colour becomes more uniform, from a light emerald green with a whitish admixture, to a dark olive, and containing numerous small veins of fibre, the conclusions may be considered as favourable to rich deposits of Asbestos. In conclusion I may add that the foregoing remarks, as regards the indications of this valuable mineral, are based on my personal geological experience, and the reliable information of the managers of the various Asbestos mines in Canada, whose opinions have greatly aided me in my recent prospection, and I trust that this pamphlet will not alone be a benefit to them, but to the Asbestos industry, which I feel assured will be one of the most prominent in the province of Quebec. LUCIUS J. BOYD, C.E., F.R.G.S.I.