112 DOLOMITE. 
had found during the previous four years numerous lime- 
stones in the Tyrol which differed from common limestones 
in effervescing very little with hydrochloric acid, and which 
were harder and closer grained than limestone; he had 
moreover noticed in Italy several statues hewn out of the 
same rock. In the following year the younger De Saussure 
contributed a paper to the same journal on the subject of 
this rock to which he gave the name Dolomite, commencing 
in these words: ‘‘ This rock deserves in all respects a special 
designation, that of ‘calcareous rock effervescing but slightly 
with acids,’ being both indefinite and unsuitable.” He also 
gives an analysis of this rock, which, though evidently 
faulty, was the first to indicate that magnesia is one of its 
constituents; his analysis is as follows: 
Calcareous Earth (or lime) - 44°29 
Argile (or Alumina) - - 5°86 
Magnesia - . - - 1°40 
Iron - - - - - 0°74 
Carbonic Acid - - - - 46°10 
Loss in Analysis - - - 1°61 
100°00 
In 1799, Mr. Tennant suggested that the slowness with 
which Dolomite dissolves in acids was due to the magnesia 
it contained, but Bournon shortly after ascribed the cause 
to the absence of water from the composition of Dolomite. 
It must be remembered that Calcite was supposed to be a 
combination of lime, carbonic acid and water, the fact that 
dry lime does not absorb carbonic acid contributing princi- 
pally to this error; moreover most limestones are hygro- 
scopic, and the small amount of water they contain was 
thought to be a necessary rather than an accidental con- 
stituent of the mineral. 
From accurate analyses made by Bucholz, Klaproth, 
Berthier, and others, about the beginning of the present 
