﻿Skey. — On the Alkalinity of Carbonate of Lime. 323 



and economical one, easy of control, and capable of delivering the gas equally, 

 continuously, and vigorously ; and I am authorized to state that Dr. Hector's 

 experience of it in the Colonial Laboi-atory testifies to the correctness of these 

 assertions. 



Art. LV. — Notes in Support of the Alleged Alkalinity of Carbonate of Lime. 

 By W. Skey, Analyst to the Geological Survey of New Zealand. 



\Eead before the Wellington Philosophical Society, 30th September, 1871.] 



In a paper which appeared in the second volume of the Transactions of this 

 Society,* I asserted the alkalinity of carbonate of lime, but the correctness of 

 this assertion having been disputed by Mr. Charles R. C. Tichborne, F.C.S., of 

 the Laboratory, Apothecaries Hall, Ireland, in a communication to the Editor 

 of the "London Chemical N'ews,"t I have re-investigated this subject and 

 extended my researches iipon it, by which I have arrived at results corrobo- 

 rative of the correctness of my statement, and which show besides that a large 

 number of salts hitherto maintained to be neutral, or about which nothing has 

 been afiirmed, are in reality alkaline. 



The latter results I will communicate in a separate form at an early date,| 

 limiting myself in this paper to an attempt to clear the ground already broken, 

 as far as I can, from the objections above referred to. 



Mr. Tichborne very courteously, and with a considerable amount of 

 plaixsibility, intimates that as the reddened litmus has the acid used to colour 

 it only weakly combined with the tinctural matter of the paper, the cai-bonate 

 of lime acts merely by absoi'bing this acid, and thus the litmus is brought 

 back to its normal colour, blue with a shade of violet ; and that therefore this 

 is not a reliable test in such a case. 



In answer to this I would ask, does not this capacity of the lime salt to 

 abstract the acid, whether acetic or carbonic (for I guarded against encumbering 

 the pi"Ocess with a double decomposition by using the latter acid), argue most 

 forcibly and sufiiciently for its alkalinity 1 



If it does not demonstrate alkalinity in such a case, then reddened litmus 

 in opposition to all received opinion is not a proper test, nor indeed one at all, 

 for ascertaining this character for any substance. 



I would ask what other condition or property is required for a substance 

 besides that enabling it to act as an alkali upon litmus, wanting which it is 

 neutral 1 



*See Trans. K Z. Inst., Vol. II., p. 150. 

 + See "Chemical News," No. 565, September 23rcl, 1S70. t See Art. LVI. 



