Natural History, —--Mineralogy. 293 
36. Apophyllite. — The a|)ophyllite of Greenland, according \ 
to Stromejer, contains, silica 51.8564 ; lime 25.2235 ; potash | 
5.3067 ; water 16.9054 = 99.2920. 
37. Heavy-Spdr. — Stromeyer has published an analysis of 
the heavy-spar of Nutfield in Surrey, from which it appears, 
that it contains no sulphate of strontian ; and further, that the 
proportions of the earth and the acid are nearly the same as in 
the artificial sulphate of barytes. This latter fact, Stromeyer re- 
marks, is of importance, from its shewing that natural combina- 
tions of bodies are constituted according to the same fixed pro- 
portions as those which are formed artificially. 
38. Strontianite. — The strohtianite of Braunsdorf in Saxony, 
which was for some time arranged as a variety of arragonite, al- 
ways contains a small portion of carbonate of lime, generally 
about 2.2 in the hundred parts. In the analysis of the stron- 
tianite of Strontian, as given by Dr Hope and Klaproth, no 
mention is made of carbonate of lime. The late experiments 
of Stromeyer, however, prove that it contains a considerable 
portion of that salt. His analysis is as follows : 
Carbonate of Strontian, - 
93.5109 
Carbonate of Lime, 
6.1658 
Carbonate of Manganese, 
0.0982 
Black Oxide of Iron, ' 
a trace. 
Water, 
0.0T55 
99.8502 
It is probable, f however, that varieties of the ipineral qf Stron- 
tian may occur without carbonate of lime, as it i^ improbable 
that so large a portion of this salt could have escaped the notice 
of chemists so distinguished for accuracy and skill as Hope and 
Klaproth. 
39. Polyhalite . — This remarkable mineral occurs in beds 
of rock-salt at Ischel in Upper Austria. It was first consi- 
dered as a variety of anhydrite ; but a more accurate exami- 
nation of its external characters have proved, that it is not only 
very difierent from that mineral, but from all others hitherto 
described ; and its remarkable chemical composition, as ascer- 
tained by Stromeyer, is an additional proof of the accuracy of 
this opinion. The following is the result of Stromeyer^ ana- 
lyses : 
