7*44 7*00 



j.46-02 16-23 16*89 



Dr. R. D. Thomson on Pegmine and Pyropine. 369 



on land, the higher subsist on the lower animals, because the 

 latter consist of the same materials of which the higher systems 

 are composed. Without the lower animals, therefore, it is ob* 

 vious the larger could not exist, and hence we may infer that 

 the inferior organizations first peopled the earth, an argument 

 opposed to the idea of some geologists, that animals have not 

 been developed in succession. ' As it is well known that 

 oysters serve as food for larger fishes, and these again for 

 more powerful species, experiments were made to deter- 

 mine the composition of oysters, herrings, and haddocks, 

 since it is highly probable that these prey on each other. 

 Portions of these fishes were well-washed in water, to remove 

 the oil and soluble matters ; the white residue was then treated 

 with alcohol and repeated digestions in aether. The resulting 

 matter, which was considered to be pure fibrine, was found to 

 have the following composition in the three species of fish 

 when burned with chromate of potash: — 



Oyster. Herring. Haddock. 



Carbon . . 53*98 53*77 53*67 



Hydrogen 



Nitrogen . 



Oxygen . 



Sulphur . .1 22*56 22*44. 



r c 



10000 100*00 100*00 



It is obvious, therefore, that fibrine can be obtained with 

 the greatest facility and of the purest form from fish. 



Can a substance be obtained from Albumen, fyc. free from 

 Sulphur ? 



In all of these kinds of fibrine, sulphur could be readily de- 

 tected ; nor was it found possible by any of the methods which 

 have been hitherto described, to obtain either from fibrinous 

 matter or from albuminous substances, a simpler body desti- 

 tute of sulphur. The analysis of the milk detailed in a pre- 

 vious part of the report, afforded excellent opportunities of 

 testing the accuracy of the idea supported by some of the con- 

 tinental chemists, that a substance can be obtained by the 

 action of potash upon albuminous substances which contains 

 no sulphur. On repeating the experiments that have been 

 detailed in books upon a considerable scale with caseine or 

 curd of milk, which were carefully conducted by William 

 Parry, Esq., late of H.M. 4th Regiment, it was uniformly 

 found that the resulting product contained sulphur. By this 

 statement, certainly it is not meant to infer that such a sub- 

 stance may not exist, but only that the writer has not been 



