RICH IN PHOSPHATE OF LIME. 281 



Near the point where it crosses the Ottowa, a branch 

 of this formation forks off towards the south, spreads 

 over a considerable extent of country between the 

 Ottowa and the head of the St Lawrence, crosses this 

 river at the Thousand Isles, among which the syenitic 

 rocks prevail, with intermixed crystalline limestones, 

 and passes into the northern counties of New York, 

 where it is extensively developed. It is there coloured 

 among the primary rocks of the State, in the published 

 geological maps of Mr Hall and Professor Emmons. 



This rock, like the altered limestones in most other 

 localities, contains imbedded in it various simple minerals 

 in greater or less quantity ; and among these apatite, or 

 phosphate of lime in grains and green crystals, is some- 

 times very abundant. Mr Logan, Provincial Geologist 

 for the Canadas, in bis Report for 1845-46, p. 94, 

 has mentioned several localities where the mineral phos- 

 phate of lime is especially plentiful ;* and Mr Hunt, 

 chemist to the survey, with whom I had the pleasure of 

 conversing upon the subject, assured me that in many 

 places this mineral formed a tenth part of the whole rock. 



One economical fact is certain — that the existence of 

 such a limestone is of undoubted value to the neighbour- 

 hood in which it exists, where it can be readily quarried 

 and burned for lime, to be used in agricultural opera- 

 tions ; and that it is of equal value as an article of export 

 for agricultural purposes, where facilities for shipment 

 or other cheap means of transport exist. Such a lime- 

 stone rock, in most easily accessible parts of Great 

 Britain, would be as sure a source of permanent wealth 

 as a mine of Californian gold. 



Another economical point is worthy of inquiry. Does 

 this mineral phosphate, in any of these localities, occur 



* At Blasdells Mills, on the Gateneau, at the Calumet Slide, and 

 above the head of Moor's Slide, near the line between Ross and 

 Westmeath. Probably many other localities are now known. 



