1908-9.] On THE ORIGIN OF THE CANADIAN APATITES. | 511 
may have been a solution of calcium chloride which was precipitated as car- 
bonate by rain water highly charged with carbon dioxide, but such a theory 
can be deduced only by a priort reasoning incapable of support by facts. 
According to the uniformitarian theory all rocks were formed by processes 
similar, to those now taking place. Now every deposit of limestone at 
present being formed is primarily or secondarily organic, and this is the 
case in practically all large unmetamorphosed masses of calcitic rock. 
In mineral veins it is true the calcite vein-stone may be considered to be 
due to the concentration of calcium carbonate from the country rock, 
but this has to do with small deposits only. 
51. It has been pointed out at an earlier place that the colouring 
matter of certain of the apatites is due to some included organic compound, 
and the question occurred whether the similar colouring of the calcite 
were due to the same cause. A number of experiments were made with 
pinkish, flesh coloured and dull red specimens, such as are found so com- 
monly with the apatite deposits. It was found that on heating, the 
characteristic organic odour was observed, and that when cooled the 
colour had gone. ‘This would indicate a similarity not only in the appear- 
ance, but also of the very nature of the pigment in certain organically 
tinted apatites, and the associated calcite of a similar colour. 
52. It has already been noted that the contact surfaces of the apatites 
and calcite show the same waxy lustre, and this and other facts already 
referred to seem to indicate that the fusion effects observable in the 
apatite are due to the action of calcite in a viscid or liquid state under the 
influence of combined heat and pressure. This being the case, traces of 
the dissolved apatite should be found in the calcite. 
53. A number of sections of the calcite were made and examined 
microscopically for indications of apatite, but in no case were they met 
with. If the apatite has been eroded by the calcite it must have been 
thoroughly dissolved. In a number of cases the calcite was examined by 
qualitative analysis which revealed the presence of phosphoric acid. Finally 
several gravimetric analysis were made with a view of determining the 
proportion of phosphoric acid present. Two of these gave the following 
results: 
I II 
Weight oficaleite min .rysiay ate eo 3.4164 Z20LLS 
Weight of crucible and ash.......... 6.1286 6.1282 
Weigh trot eErcibles yr ter. cles nie aie ee 6.1260 6.1260 
Wieisit Obrashe ma Wnacy danse Sy hy OROOZZ 0 .0026 
Wieishtoot uniter asheet ceri ccic sla cne. 0.0002 0.0002 
Weight ef} midges: phos. 2. on. ©. 0.0020 0 .0024 
Percentage of phosphoric acid....«.. 0.221 0.191 
