1908-9.] On THE ORIGIN OF THE CANADIAN APATITES. 509 
most marked degree. In the case of pink and green specimens the colour 
gradually faded leaving a straw colour which was permanent after the 
experiment. It would appear, therefore, that the colouring matter of 
the Canadian apatites is, in the majority of cases, largely organic. 
V.—EVIDENCE FROM THE PuHysICAL CHARACTERISTICS OF APATITE. 
42. In eruptive rocks the microscopic crystals of apatite are among 
the first to separate and always maintain their clear outlines. Speaking 
in particular of those in the eruptives of Puy de Dome, Gonnard and 
Adelphi 29 remark that they nearly always remain intact no matter 
how its rock has been contorted by violent motion before or during the 
second stage, and retain their clear outlines. 
43. When, however, we turn from the microscopic to the larger 
examples, a most striking difference is to be noted between those which 
occur, as in Norway, in pyroxenite without calcite, and those as in Canada 
in which calcite is usually present. In the former case the apatite crystals 
are characterized by the clear cut outlines and sharp edges observable 
in the microscopic specimens; in the latter the faces and edges of the 
crystals always exhibit a most extraordinary appearance of fusion, which 
formed the object for a very careful examination, of all material avail- 
able in the University museum. 
44. The peculiar waxy lustre of the crystal faces, the rounding of 
edges and coigns, the more or less complete corrosion of the crystals 
themselves were extremely striking peculiarities. In numerous cases — 
where the crystals were very much corroded, particles of calcite filled the 
corroded parts. Where shallow depressions were observed on the crystal 
face, an examination of the calcite originally in contact revealed corres- 
ponding elevations which exactly fitted. This was most noticeable in a 
specimen of apatite in calcite collected by Dr. Coleman in Sebastopol. 
In a specimen of his from South Burgess, the action had continued to the 
greatest extreme. In this the apatite had been entirely removed, leaving 
a negative crystal. In this and every other case the surfaces of calcite 
which had been in juxtaposition, showed the same waxy lustre observed 
in the affected apatites. 
45. In several specimens in the University museum the apatite 
crystals had been broken and recemented, the recemented parts being in 
slightly altered positions. These extreme cases of alteration such as 
29 @, R. 126 : 1532: 
