fiOTTEN-STONB. 
51 
Hard BoltefirSlone, hit less indurated than specimen 2, 
colour nearly similar. 
Alurrtine 84 
Silex 3 
Carbonate of Lime 5 
Oxide of Iron. O 
Inflammable matter and loss 8 
100 
4. Soft Rotten-stone, i. e. with a texture much more loose or 
earthy than in the other specimens. 
Alumine 87 
Silex 4 
Carbonate of Lime 0 
Oxide of Iron O 
Inflammable matter and loss 9 * 
100 
If we compare the foregoing analysis with those, which 
mineralogists have given us of limestones, we shall find, that 
the chief difference (in a chemical point of view) between 
rotten stone and certain varieties of limestone, exists in the 
• It should bt observed that the “ loss,” in these analysis, never 
exceeded V5 ; hence the proportion of “ i/iflununiible matter" may be 
stated as varying from 5’5 to 7‘5* At the time of making my experi- 
ments on rotten-stone, the principal object in view was to ascertain the 
predominating earth in its composition, and nut determiniug the 
nature of the inflammable matter, it was placed With the loss ; — there 
can be little doubt, however, of its being curlwi. Silex was found in 
all the specimens examined. Carbonate ef lime only in the harder 
varieties, and not constantly in those. Two or three sprciineus 
analysed, in all external respects similar to No. 3, were without it. 
Oxide of Iran was only present in the harder rotten-stones. — Tlie 
actual constituents, therefore, of genuine or perfect rotten-stone 
(that is, rotten-stone in which the disintegration of the original substance 
is complete) may be stated to be alumine, silex, and infiammsble matter 
( tarh'iu ?) 
larger 
£2 
