TWENTY-FOURTH ORDINARY MEETING. 299 
tuents of the country rock which they may happen to traverse, such 
as felspar, quartz, calcite, pyroxene, apatite, mica, etc., or with some 
of these minerals mingled together. The gangue adheres strongly to 
the wall-rock which to a certain distance in is often penetrated by a 
greater or less proportion of the veinstone. 
All writers on this subject have dwelt on the great irregularity 
and the puzzling character of the apatite deposits. At first, the de- 
posits were supposed to be beds, but they are now pretty commonly 
regarded as being rather of the nature of veins of an irregular and 
unusual nature. Regular veins, generally of small size, filled with 
apatite or having this mineral as one of the veinstones have also 
been described by writers on this subject. On the 2nd lot of the 
third range of the township of Bowman in Ottawa county, I have 
seen a well defined small isolated vein of pyroxene, cutting gneiss 
and holding masses of apatite along its centre. The mine at Little 
Rapids on the Liévre appears to be in a large vein. These are prob- 
ably instances of regular veins of very ancient date. But in the 
great majority of cases the deposits, whether of the pure phosphate 
or of a mixture of this with other minerals, appear to differ from 
true fissure veins and to be extremely uncertain and capricious in 
their forms. 
The mineral is often much mingled with the pyroxenite, but it 
always has a tendency to form itself into floors and branching veins, 
having two principal local courses. From an attentive study of 
these in several of the mines which have been opened in the Liévre 
valley, I have come to the conclusion that these lines of deposit mark. 
approximately the original jointing of the rock. These ancient joints 
belonged to three sets, two nearly vertical intersecting each other, 
and one nearly horizontal, analogous to the three sets of dry joints of 
more recent date, which we usually see in massive rocks at the 
present day. In the course of the disturbances to which these phos- 
phate-bearing pyroxenites and gneisses were subjected, the angular 
masses into which they had been divided by these joints became in 
places separated and displaced, leaving the spaces which are now 
filled with the apatite. The process—one of segregation—was 
similar to that by which the irregular veins in other varieties of the 
Laurentian rocks have been filled with quartz and orthoclase or 
calcite and its associated minerals. Indeed it has been pointed out 
that the tribasic phosphate of lime shows an unusually strong ten- 
