MINERALS AND GEOLOGY OF CANADA. 157 
silver.* Composition: sulphuric acid 34°33, baryta 65.67. This 
mineral occurs abundantly in many parts of Canada. In the Lau- 
rentian series of metamorphic strata, it forms considerable veins, 
usually accompanying galena: as in the townships of Lansdowne, 
Leeds Co., C. W.; Bathurst, Lanark Co.; McNab, Rentrew Co. ; 
Dummer, Peterboro’ Co.; and elsewhere. Red crystals were dis- 
covered by Mr. Murray on Iron Island, Lake Nipissing. It occurs 
likewise, in connection with the trap dykes of Lake Superior and 
the north shore of Lake Huron, as at Spar Island, &c., besides 
being found in some of the copper-ore veins o! the Bruce mines. 
Heavy spar has also been met with in the serpentines and other rocks 
of the eastern metamorphic region, south of the St. Lawrence ; and 
occasionally in cavities in the Niagara limestones of the west. It is 
employed somewkat largely in the manufacture of paints, and is too 
often used in this connection asa fraudulent substitute for white lead. 
Heavy spar is also the principal source of the baryta salts of the 
laboratory. 
Celestine or Sulphate of Strontia:—White, grey, pale-blue, Xe. 
In lamellar and fibrous masses, and in Trimetric crystals, often 
closely resembling those of Heavy Spar. A common combination 
is shewn in Figure 50. H.3:0-3°5; sp. gr. 3:9- 
4:0. Before the blow-pipe, it (generally) de- — 
crepitates, fuses, and imparts a red coloration 
to the point of the flame. (See also the note Fig. 50. 
under Heavy Spar.) Composition: sulphuric 
acid 43°6, strontia 54:4. Celestine occurs with small crystals of 
dolomite, gypsum, fluorspar, blende, and other minerals, in cavities 
of the Niagara limestone, as in the district around the Falls, and in 
the vicinity of Owen Sound, &c. Drummond’s Island, Lake Huron, 
is likewise a noted locality of this mineral. It occurs also, occasion- 
ally, in crystalline limestone, as in the neighbourhood of Kingston. 
Celestine is the chief source of strontia salts, used in pyrotechny to 
* To detect sulphur, in any form in mineral bodies, fuse a small quantity of the substance 
under examination, with carb. soda and a very little korax, on charcoal, in a good reducing 
flame. Detach the fused mass, moisten it, and place it on a piece of bright silver, or on 
lead test-paper. (A coin or glazed visiting-card may be substituted for the purpose.) If 
sulphur be present, a yellowish, brown, or black stain will result. See Canadian Journal, 
New Series, Vol. III., p. 217-18. Both sulphate of baryta and sulphate of strontia dissolve 
readily in carbonate of soda before the blowpipe, resembling, in this respect, alkaline sul- 
phates. Sulphate of lime (with all lime salts) ou the other hand, requires the addition of 
a little borax to promote solubility. 
