454 Transactions. — Chemistry. 



are operating — an estimate which, though still overstating the degree of this 

 solubility, does so to such an msignificant extent that the excess need not 

 be taken into account for practical purposes. 



I should state that in testing the solubility of calcic carbonate I use lithic 

 carbonate for the precipitant, as the salts of lithia have far less solvent 

 power over the calcic carbonate than those of soda have ; with strontia 

 carbonate the reverse seems to hold. 



Operating in this manner I got results which assign the ratios by weight 

 of the solubility of the earthy carbonates in water as follows : — 



Calcic carbonate . . . . . . . . 1 part in 75,000 parts. 



Strontia carbonate . . . , . . 1 ,, 300,000 ,, 



Baryta carbonate . . . . . . . . 1 ,, 18,000 ,, 



Calcic carbonate therefore appears to be soluble in water at a little under 

 the rate of one grain per gallon instead of two, the lowest estimate hereto- 

 fore assigned to it. The correctness of the rate of solubility of the strontia 

 carbonate as given by Bineau is thus confirmed, while that of the baryta 

 compound appears to be under one-fourth of that popularily assigned to it. 



Art. LXIX. — On the Presence of Nickel in the Auckland District. 

 By J. A. Pond. 

 [Read before the Auckland Institute, 2Srd July, 1877.] 

 In bringing this subject before the Institute, I have not done so with the 

 intention of chronicling any valuable discovery, but simply to bring before 

 the members the fact that we have the metal nickel existing in several parts 

 of the province ; nor can I lay claim to being the first to note the presence 

 of this metal in New Zealand, as I find in the annual report on the Colonial 

 Museum and Laboratory for 1876, Mr. Skey mentions its presence in troilite 

 obtained in the geological survey of the Parenga Eiver and Fox Glacier, 

 Westland, by Mr. S. H. Cox. 



My first acquaintance with the nickel of this province was on receipt of 

 some stone from Mahurangi, about two years since, said to contain silver. 

 This, however, was not present, but on further examination I found that 

 the stone contained either nickel or cobalt, but the small amount at my 

 disposal prevented my deciding in reference to these two metals. On receipt 

 of a larger portion I succeeded in isolating nickel, but finding it in too small 

 a quantity for commercial value, I did not pursue the matter further. A 

 few months since I obtained some more stone of a similar character from 

 the Ivaipara, and found this to be a serpentine which also yielded nickel. 



