( 



New Instrument for Specific Gravities. 263 



saldj one character alone remains among those described as be- 

 longing to the sulphate of strontian, of this locality, which can be 

 considered as distinguishing it from barytes; but that is an important 

 one. In consequence of that part of your note referring to its sp. 

 gr. I carefully repeated the operation with two distinct mstruinents 

 and two distinct pieces of the mineral. The first with a pair of delicate 

 scales for weighing gold, gave 3.913 — the other with Nichol- 

 son's Portable Balance, gave 3.916 which (together with my former 

 trials) renders It highly probable, if not certain, that the mineral is 

 strontian and not barytes, the sp. gr. of which is, by all authorities, 

 stated at several tenths above 4.0. 



From a note by Dr. Cooper, In his edition of Thomson, Vol. I, 

 p. 289, in which he says that " all the salts of strontian whh muriate, 

 nitric and acetic acids, give a red color to flame, when cloth impreg- 

 nated by them, is dipped Into alcohol and burnt." I was Induced to 

 make the following experiments with nitrate of lime, oxalate of lime 

 and acetate of lime, (carbonate of hme dissolved in vinegar.) 



Nitrate of lime burnt in alcohol, gave a blue flame, edges red. 

 Do. in the candle, gave a much lighter red, approaching lilac. 



Oxalate of lime in alcohol, gave no redness- 

 Do. in the candle, do. do. 



Acetate of lime in alcohol, gave scarcely any. 

 Do. in the candle, gave very light red. 



The slight reddening observed in the nitric solution, was attributed 

 to the presence of muriatic acid, which I believe generally exists in 

 the nitric acid of commerce. And the same may be the case with 

 the acetate of hme.* 



Art. VIII. — A new Instrument for talcing Specific G 



Lieut. J. W. Baddeley, R. En. Up. Can. 



EXPLANATORY LETTER 



TO THE EDITOR. 



Kingstjn, (U. C.) April 16, 1830. 



Dear Sir — 1 lay no claim to invention in submitting to your notice 

 and that of the public, the following description of an instrument for 

 taking the sp. gr. of minerals, the principle on which it is con- 

 structed is, we all know, "as old as tlie hills ;" there may be, however, 



* I request the Indulgence of your readers, for the foregoing observations, as com- 

 ing from one at the threshold of scientific inquiry. 



