508 TRANSACTIONS OF THE CANADIAN INSTITUTE. (Vou. VIII. 
37. The nature of the colouring matter of otherwise colourless miner- 
als, is a problem of general interest to mineralogists, but it has an added 
interest when we investigate the colour of apatite. Von Kraatz-Koschlau 
and Wohler, in an interesting research whose results were published in 
1899’ pointed out the very suggestive fact, that the colouring matter 
in a number of the crystalline minerals examined, was to a greater or less 
extent organic, among those giving this result were fluorite; barite; 
celestite; anhydrite; salt; calcite; zircon; smoky topaz; amethyst; 
microcline; rubellite; topaz and apatite. 
38. The European apatites examined were green and violet trans- 
parent specimens from Saxony. On being heated they gave off an empy- 
reumatic smell, gradually lost their colour, and exhibited strong colour 
phosphorescence, which continued only as long as the colour and odour 
remained. Quantitative analyses made with copper oxide in the usual 
way gave results as follows: 
CaO aware. Stensuh cis anertss 0.003 gr. 0.066% 0.018% C. 
PARA ete Heretic Sioevole vaste 0.0055 gr. 0.122% 0.014% H. 
39. Green apatite from Canada, on being subjected to the same 
tests gave the organic smell, the greenish fluorescence, but the speci- 
mens had a permanent yellowish colour, evidently due to inorganic colour- 
ing matter. Their general conclusions were that apatites from European 
localities were to be referred to that class of minerals whose colour is due 
to organic material only, while those from Canada were placed by them 
in the second group whose colouring matter is partly organic and partly 
inorganic. 
4.. It was made quite evident from their researches that organic 
colouring matter and colour-phosphorescence always occur together, 
It is interesting to note in this connection that some of the phosphorites 
from Spain show this phenomenon.”® 
41. The apatites from various Canadian localities in the collections 
of the University of Toronto may be referred to three colour types (a) 
green from very light to quite dark, (b) flesh coloured from light pink to 
almost brown, and (c) bluish from light to almost black. Crystals of each 
of these types were examined for pyro-phosphorescence with the result 
that the bluish specimens which were the least numerous were found to 
be practically free of phosphorescence, while the pinkish show it in the 
27 Tch. min, u. Pet. mitth. 18> 304-447-1889, Von Kraatz-Koschlau and Lothar Wohler — 
Naturliche Farbungen der Mineralien. 
28 Penrose, p. 54. 
