ON MATTER AND FORCE. 67 



quality of the ponderable matter that enters 

 into or is thrown out of any system. 



The slight progress that has hitherto been 

 made is seen in the fact that there are many 

 persons at present able to rest in the belief 

 that the inseparability and conservation of 

 matter and force are our main principles and 

 our best guides in the abiological sciences ; 

 whilst most persons think that in the biological 

 sciences the perfect or imperfect separability 

 of matter and force, and the constant creation 

 and annihilation of . energy, are most likely to 

 be the true foundations on which the sciences 

 that include life must be built. 



But, if this be so, then the creation and 

 annihilation of force must be established by 

 positive proof, and must not rest only on as- 

 sumptions which are directly opposed to the most 

 certain knowledge we possess regarding ponder- 

 able matter and force in other branches of 

 science. 



We know now that in all living things no 

 separate or peculiar matter is present. 



The stuff which takes part in the living 

 actions, and the forces which are inherent in 



