82 Essay on the Transition Rocks of the Cataraqut. 
It is on the exposed surfaces of this rock, particularly on the low 
shores of the lake on the south side of Kingston, that we find those 
beautiful masses imbedded, which have excited so much enquiry and 
which were alluded to in a former number of this Journal. 
They are composed of a mixture of barytes, strontian, crystallized 
carbonate of lime, iron pyrites and zinc ; sometimes the first two in- 
gredients alone are present; sometimes the mineral is apparently a 
component part of the rock, at others it is evidently a mere ball or 
mass enveloped by it and easily detached. Occasionally the car- 
bonate of lime is slightly yellow or flesh colored, but the crystals, 
always large and without distinct form, are generally in curved layers 
and magnesian. Masses as large as a man’s head have recently been 
discovered, and these, when broken, present some beautiful speci- 
mens, the blades or fibres shining with the lustre of new satin. 
This substance was supposed, for a long time, to be tremolite, and 
certainly it bore the outward look of that species named after Lake 
Baikal, but its obvious specific gravity should have caused doubt; it 
was first described in the opening volume of the Transactions of the 
Quebec Society of Natural History, and from the specimen I used 
in analysing it, I had every reason to believe that it was a sulphate 
of barytes. Since that time a very attentive mineralogist, Mr. Bad- 
deley, has given an account of it in this Journal, and pronounced it 
to be strontian. The question is however decided ; both were right 
and both were wrong, and a conjecture hazarded in the interim has 
been verified by Professor Thomson, to whom the mineral was sent 
by the Secretary of the Montreal Natural History Society. It is 
stated by that eminent mineralogist to be a new substance, and he 
proposes to call it baryto-sulphate of strontian.* I am not, howevels 
yet convinced but that many specimens of this substance contain pure 
sulphate of barytes only, in some of their portions, whilst others cou 
sist also of pure sulphate of strontian, although I am perfectly ready 
to admit that the masses generally are those of the new substance 
thus named.f 
(To be continued.) 
Pa rtm |e 
* According to the Professor’s analysis, it contains eleven atoms of strontian and 
five of baryta. 
t In a communication to Dr. Holmes, I had previously suggested that it might be 
a barytic sulphate of strontian, as I felt convinced that Mr. Baddeley’s opinion aad 
to the strontian was correct. With respectful deference to the Professor, 1 think 
Kingstonite would not be a bad name for it. 
ee 
