TRANSACTIONS OF THE SECTIONS. 
41 
In this state it is colourless and inflammable : it has a powerful, 
and to most persons a very disagreeable smell. Caustic potash de¬ 
composes it instantly, acetate of potash being formed, and probably 
carbonate of potash. Tt forms acetate of lime also when slacked lime 
is added to it. It softens copal, but dissolves very little of it. When 
diluted with water it does not comport itself as alcohol of the same 
specific gravity does ; 50 measures of it mixed with 50 of water at 
the temperature of 54, were raised in temperature to 61, and a con¬ 
siderable quantity of air was extricated ; the mixture brought again 
to the temperature of 54, measured but 96*5 measures, and its spe¬ 
cific gravity was *9861. Alcohol diluted so as to have specific gra¬ 
vity *911, when similarly treated, measured 9 8, and its specific gravity 
was *9659. 
Litmus-paper immersed in it is not reddened, but on exposure 
to the air the fluid evaporates and leaves the paper permanently 
red. 
It mixes with water in every proportion, and water may be sepa¬ 
rated from it by means of carbonate of potash as from dilute alcohol, 
which is not the case with pyroxylic spirit. 
On the Chemical Constitution of Fossil Scales , as illustrative of the 
nature of the Animals from which they have been derived . By 
Arthur Connell. 
The difficulty of determining merely from external characters 
whether a fossil scale has belonged to a fish or to a saurian animal, 
and the geological interest which that problem frequently possesses, 
render it desirable to know whether chemical means are capable of 
solving it. 
Mr. Hatchett ascertained that the scales of recent reptiles consist 
chiefly of a horny substance, whilst those of fish contain a consider¬ 
able proportion of phosphate of lime, and are of the nature of bone. 
Chevreul confirmed his observation as to fish-scales; and the author 
has found that the scales of small recent crocodiles contained little 
more than one per cent, of incombustible earthy matter, although in 
the carinated dorsal scales the amount extended to about 3 per cent. 
When fish-scales are fossilized we may therefore expect that the bone- 
earth will remain, and the perishable animal substance will either dis¬ 
appear without any substitution, or be wholly or in part replaced by 
siliceous or calcareous matter; whilst, on the other hand, if a saurian 
scale is mineralized it ought to consist almost entirely of some re¬ 
placing substance, such as siliceous or calcareous matter, coming in 
place of the decaying animal matter and of little or no bone-earth. 
The author has analysed fossil scales from the three following 
localities, and the result of the analysis he conceives to show the 
whole of them to have belonged to fish : 
