2 
MUSEUM BULLETIN NO. 27. 
the serpentine and chryso tile-asbestos, and it is largely as a result of 
his suggestion that the present work was undertaken. Mr. Harvie 
also very' kindly assisted the writers on one or two occasions in the 
collection of material, and has from time to time supplied them with 
specimens which he had himself collected. 
When the International Geological Congress held its twelfth session 
in Canada in 1913, an excursion (A5) 1 was made to the asbestos and 
chromite deposits under the direction of T. C. Denis and J. A. Dresser, 
with R. Harvie as guide. This excursion proved of exceptional interest 
to mineralogists, who were able to collect specimens of many of the 
minerals now described in this bulletin. 
The writers wish to acknowledge the courteous treatment they have 
in all cases received from the management of the various asbestos and 
chromite pits visited, where every facility was freely accorded them, 
both for the examination of the deposits and also for the collection of 
material. They are indebted to John Stansfield of McGill university, 
who has made most of the microphotographs, and to G. G. Clarke of the 
Geological Survey, who made the remainder of the series. It is with 
great pleasure that the writers take this opportunity to record their 
indebtedness to R. A. A. Johnston, mineralogist and curator, for much 
helpful criticism and many useful suggestions while the work was in 
progress, as well as for his kindness in reading and correcting the final 
manuscript. 
Both the collection of the material and its investigation were made 
independently by the writers until the present summer, when, at the 
suggestion of Mr. Johnston, it was decided that the results of the work 
might most conveniently be combined and published as a joint bulletin 
Accordingly E. Poitevin spent one month at McGill university col 
laborating with R. P. D. Graham, with this end in view. The 
results of this collaboration are set forth in the following pages, which 
are believed to present a fairly complete account of the mineralogy of 
Black Lake area. 
The crystallographic work was done at Harvard university under 
the direction of Professor C. Palache, at Cornell university and in the 
mineratogical laboratory of the Geological Survey, by Poitevin; and in 
Professor Beck’s laboratory in Vienna and at McGill university, by 
Graham. Some of the chemical analyses have been made in the chemical 
laboratory of the Department of Mines by M. F, Connor, and the 
remainder at McGill university. 
Several of the minerals are exceptionally well crystallized and in 
many cases they further exhibit features, such as unusual habits, forms, or 
1 Coitgr&s gMogique international, cornpte-rendu de la XII session, Canada, 1913, pages 968 and 
969, 
