Toads enclosed in Stone and Wood. 315 
the compact sandstone was dead, and the bodies of most of them so much 
decayed, that they must have been dead some months. The greater 
number of those in the larger cells of porous limestone were alive, No. 1, 
whose weight when immured was 924 grains now weighed only 698 
grains. No. 5, whose weight when immured was 1185 grains, now 
weighed 1265 grains. The glass cover over this cell was slightly cracked 
so that minute insects might have entered ; none however were discovered 
in this cell; but in another cell whose glass was broken, and the animal 
within it dead, there was a large assemblage of minute insects, and 
a similar assemblage also on the outside of the glass of a third cell. In 
the cell No. 9, a Toad which when put in weighed 988 grains, had 
increased to 1116 grains, and the glass cover over it was entire, but as 
the luting of the cell within which this Toad had increased in weight was 
not particularly examined, it is probable there was some aperture in it by 
which small insects found admission, No. 11 had decreased from 936 
grains to 652 grains. 
When they were first examined in December, 1826, not only were 
all the small Toads dead, but the larger ones appeared much emaciated, 
with the two exceptions above mentioned ; we have already stated that 
these probably owed their increased weight to the insects which had found 
access to the cells and become their food. 
The death of every individual of every size in the smaller cells of 
compact sandstone appears to have resulted from a deficiency in the 
supply of air in consequence of the smailness of the cells, and the 
impermeable nature of the stone; the larger volume of air originally 
enclosed in the cells of the limestone, and the porous nature of this stone 
itself (permeable as it is slowly by water and probably also by air) seems 
to have favored the duration of life to the animals enclosed in them 
without food. 
It should be noticed that there is a defect in these experiments arising 
from the treatment of the twenty-four Toads before they were enclosed 
in the blocks of stone. They were shut up and burried on the 26th of 
November, but the greater number of them had been caught more than 
two months before that time, and had been imprisoned altogether in a 
cucumber frame placed on common garden earth, where the supply of 
food to so many individuals was probably scanty and their confinement 
