THE 



CANADIAN NATURALIST 



AND 



^uavtcvUt f auntal of ^^icttcc. 



NOTES ON DAWSONITE, A NEW CARBONATE. 



By B. J. Harrington, B.A., Ph.D. 

 Chemist and Mineralogist to the Geological Survey of Canada. 



In the present paper I wish to describe a new mineral, which 

 on account of its peculiar composition seems to be of more th.-in 

 ordinary interest. 



In 1862 Messrs. J. H. and G. Gladstone described, under the 

 name of Hovite, a mineral which they suggested might be re- 

 garded as a double carbonate of alumina and lime.^^ On the 

 ground, however, of a carbonate in which alumina or sesquioxide 

 of iron enters being unknown to chemistry, and from the fact 

 that the so-called Hovite occurs mixed with Collyrite, a hydrous 

 silicate of alumina, Dana regards the alumina as belonging wholly 

 to the admixed material, and considers the lime to be present in 

 the state of bicarbonate. With regard to it he says : " Although 

 the bicarbonate referred to is known only in solution, the most 

 likely condition for finding it in the mineral kingdom is in one 

 of the hydrous silicates of alumina, like collyrite, in which there 

 is present much water, loosely held ; the mineral therefore is 

 most probably a carbonate of the formula above given QCaO + 

 ^HO) CO2 + aq ; especially since a carbonate in which AI2O3 

 or Fe203 enters is, as the authors (the Messrs. Gladstone) 

 admit, yet unknown to chemistry." 



Now although the formation in the laboratory of a carbonate 



*Phil. Mag., IV. xxiii. 462, 18G2. 

 t Mineralogy, 5th ed. p. 709. 



Vol. VII. u Ko. 6. 



