THE CATTEDOWN BONE CAVE. 
25 
but while some were so friable as to crumble at the touch if dry, 
or to fall into a kind of paste if wet — and to require great care 
in drying — others again were fairly solid, and some really dense 
and hard. These differences existed between bones lying close 
together, parts of the same finds, and in some instances of the 
same animal ; and it will easily be understood that bones exposed 
to the air continuously would be in a very different condition 
from others enclosed in stalagmite, or in a dense mass of clay 
permeated with animal matter. 
Such differences were recognized from the very first by the 
investigators of cave deposits. Mr. W. Martyn, in 1809, stated, 
in his "Attempt to Establish a Knowledge of Extraneous Fossils 
on Scientific Principles," that fossil bones often retained "a 
portion both of the gelatine and phosphoric acid in their com- 
position, particularly in their interior parts, the surface only 
having undergone a privation or loss of these principles." Dr. 
Buckland observed that there was less animal matter in the bones 
of Oreston than in those of Kirkdale. 
So Mr. Clift, reporting on Mr. Whidbey's find of 1822 (Phil 
Trans.) at Oreston, noted that there was "a considerable difference 
in various specimens . . . that the loss of animal matter, and 
consequent decay or decomposition of fossil bones, depends very 
much upon the nature of the soil in which they are deposited ; " 
and that bones of the mastodon from Ohio, and the bear from 
Gaylenreuth, retained their animal matter so as to keep their 
form when deprived of their earth by means of muriatic acid. 
Analyses by Mr. Brande of rhinoceros remains found at Oreston 
in 1816, gave .02 of animal matter only for a bone, and .06 with 
water and loss for a tooth ; but he remarked that he had never 
met with fossil bones so purely earthy. Analyses by him — of a 
rhinoceros tooth found at Brentford gave .04 of animal matter 
and water ; of the tibia of a hippopotamus found at the same 
place, .05 of animal matter solely ; while the rib of a fish from 
the Lyme Regis Lias contained .03. Vast as is the time, there- 
fore, which divides us from the era of the Lias, even it has not 
been long enough — if time were all — to get rid of the distinctly 
organic constituents of the fish of the Liassic sea. 
In their natural state the organic constituents of bones may be 
put on an average at a third, varying in the human subject from 
1 to 1*6 to 1* to 2*3. In the femur of an ox Heintz gives the 
