XXII. Observations on Arragonite, together with its Analysis. By 
pr the Rev. John Holme, A.M. F. L.S. 
Read April 6, 1813. 
Ture is no substance, which has of late years more excited the 
attention of chemists and mineralogists, than Arragonite, so called 
from the place where it was originally discovered. As, the only 
anomaly in the Abbe Haüy's Theory of Crystallization, it has 
long been suspected that in its chemical analysis it would be 
found to differ from the carbonates of lime, with which it has 
been hitherto classed. "This suspicion has been augmented by 
other circumstances of external character, beside those of cry- 
stallization and mechanical division. It is much harder than 
any of the common crystallized carbonates of lime, so as to 
scratch them easily. Its specific gravity is also greater, being 
2.9465*, instead of 2.718-+, which is the specific gravity of com- 
mon calcareous spar. Yet the most careful analysis of Arragonite 
has not brought to light any fact at variance with the received 
opinion concerning its composition. “ The difference in its pri- 
mitive form," it is said, ** does not result from any difference in 
its chemical combination T." 
Under these circumstances I was induced to undertake the 
analysis of Arragonite. The result, I trust, will prove that it is 
not, as has been so often asserted, a pure carbonate of lime; and 
* Haüy. T Thomson’s Chemistry, vol. iv. ed. 4, p. 347. 
t Brongniart's Mineralogy, vol. i, p. 222, | 
oe XI . 21 £P nat 
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