Toads enclosed in Slo)ie and frood. 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 \veighed 988 grains, had 

 increased to 11 16 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 sniallness 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 hurried 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 



