THE HISTOET OF A DISCOVERY. 49 



Geological Survey of the province, from one of the limestones 

 of the Laurentian series occurring at the Grand Calumet, on 

 the river Ottawa. 



" Any organic remains which may have been entombed in 

 these limestones would, if they retained their calcareous cha- 

 racter, be almost certainly obliterated by crystallization ; and 

 it would only be by the replacement of the original carbonate 

 of lime by a different mineral substance, or by an infiltration 

 of such a substance into all the pores and spaces in and about 

 the fossil, that its form would be preserved. The specimens 

 from the Grand Calumet present parallel or apparently concen- 

 tric layers resembling those of Stromatopora, except that they 

 anastomose at various points. What were first considered the 

 layers are composed of crystallized pyroxene, while the then 

 supposed interstices consist of carbonate of lime. These 

 specimens, one of which is figured in Geology of Canada, 

 p. 49, called to memory others which had some years previously 

 been obtained from Dr. James "Wilson, of Perth, and were then 

 regarded merely as minerals. They came, I believe, from 

 masses in Burgess, but whether in place is not quite certain ; 

 and they exhibit similar forms to those of the Grand Calumet, 

 composed of layers of a dark green magnesian silicate 

 (loganite) ; while what were taken for the interstices are filled 

 with crystalline dolomite. If the specimens from both these 

 places were to be regarded as the result of nnaided mineral 

 arrangement, it appeared to me strange that identical forms 

 should be derived from minerals of such different composition. 

 I was therefore disposed to look upon them as fossils, and as 

 such they were exhibited by me at the meeting of the American 

 Association for the Advancement of Science, at Springfield, in 

 August, 1859. See Canadian Naturalist, 1859, iv., 300. In 

 1862 they were shown to some of my geological friends in 

 Great Britain; but no microscopic structure having been 

 observed belonging to them, few seemed disposed to believe 

 in their organic character, with the exception of my friend 

 Professor Eamsay. 



" One of the specimens had been sliced and submitted to 

 microscopic observation, but unfortunately it was one of those 



E 



