202 Bigshy— On the Laurentian Formation. 
Carbon.—This substance is indispensable to organic structure, and 
is in very great quantity in the Canadas, almost always near to, or 
imbedded in, marble, which is often at the same time rich in phos- 
phate of lime, and contiguous to deposits of magnetic oxide of iron 
(forming small hills). Four of the principal constituents of animals 
and plants are thus brought together in the Laurentian group; and 
with every probability that they have been employed as such. The 
presence of carbon in the state of graphite, wnoxidized, in meta- 
morphic rocks, was first urged by Sterry Hunt on the attention of 
geologists as showing that a temperature of ignition was not required 
for metamorphism. Sir W. Logan* found carbon so largely dis- 
seminated in the marbles of the Lower Ottawa (Grenville, Chatham, 
and Gore Counties) that he proposes to call them ‘plumbaginous 
marbles.’ Durocher mentions four places in Sweden and Norway in 
which graphite is collected for economical purposes.f Carbon in all 
its forms is derived from vegetables, and usually by aqueous means. 
Therefore there must have been vegetation before the Laurentian 
rocks assumed their present condition. 
Phosphorus is found in many shapes, and in great quantities in the 
Laurentian rocks, in union with lime, alumina, silica, fluor, lithia, 
soda, iron, copper, and zinc. This element presents an aggregate of 
combinations which must have taken much time to produce, if we 
are to apply to mineral processes the same reasoning that we do to 
the vital, inferring from the number and variety of organic remains 
in any given bed that it had endured long as a stage. Phosphorus 
is plentiful in almost every geological formation, excepting, perhaps, 
the Mid-silurian, the so-called Cambrian, and the Huronian. It 
seems to be a ubiquitous element, being found in iron, coal, granite, 
lava, most sedimentary rocks, soils, and all waters. (In the 
Appendix is given a list of its principal formations and locali- 
ties.) Phosphorus generally occurs as a phosphate of lime, mi- 
nutely disseminated through nearly all rocks, and in a vast quantity, 
viewed in the large. ‘Chemical tests may be required for its 
detection; but sometimes the rock-surfaces are roughened with 
crystals of apatite. It is in the marbles of Canadat{ that this phos- 
phate particularly abounds. In the coarse red marble of Burgess 
Township (River Ottawa) it forms (diffused as apatite) one third of 
the whole deposit, being intermixed with other common minerals. 
Beds similarly charged with phosphates are in the vicinity. The low 
country about the River St. Lawrence, south of these Laurentian 
deposits, as well as that between the Ottawa and Lake Erie, is 
strewn with blocks of phosphatic marbles. Near Prescott, I broke 
up one, weighing a ton, full of beautiful druses of apatite. Phosphate 
of lime occurs in the white marble of St. Paul’s Bay and Malbay in 
Lower Canada, This mineral§ is found in the marbles of Norway; 
ae 
Geol. Survey, 1853-56, p. 641. 
Loe. cit. p. 39. t Report, 1863, p. 26. 
I allude to the two following deposits of this phosphate only with the view of 
showing the great quantities in which it occurs almost pure. At Logrosan, near 
Costanoza, in Spain, phosphorite (so called) occurs in vertical layers, 2-22 feet 
mn 
