388 THE CANADIAN NATURALIST. [Vol. ix. 



when charged like a condenser. In this view of the matter the 

 normal condition of the muscle is one of charge, of elongation. 

 Contraction results from the simple elasticity of the muscle 

 itself, the function of the nerve being only that of a discharger. 

 Whether this theory represents the actual fact or not, in all its 

 details, it is supported by the existence of rigoi^ mortis, by the 

 continued relaxation of muscle during the flow of the current, 

 by the cessation of contraction on the free access of blood, and 

 by many other phenomena otherwise difficult to explain. 



" From this brief review, does it not seem probable that the 

 phenomenon of muscular contraction may be satisfactorily 

 accounted for without the assumption of ' vital irritability,' so 

 long invoked ? May it not be conceded that the theory that 

 muscular force has a purely physical origin is at least as probable 

 as the vital theory ? 



" Time would fail me to discuss the many oth'cr phenomena 

 of the living body which have been found, on investigation, to 

 be non-vital. Digestion, which Prout said it was impossible to 

 believe was chemical, is now known to take place as well without 

 the body as within it, and to result from non-vital ferments. 

 Absorption is osmotic, and its selective power resides in the 

 structure of the membrane and the diffusibility of the solution. 

 Respiration is a purely chemical function. Oxyhsemoglobin is 

 formed wherever haemoglobin and oxygen come in contact, and 

 the carbon dioxide of the serum exchanges with the oxygen of 

 the air according to the law of gaseous diffusion. Circulation 

 is the result of muscuhr effort both in the heart and capillaries, 

 and the flow which takes place is a simple hydraulic operation. 

 Even coagulation, so tenaciously regarded as a vital process, has 

 been shown to be purely chemical, whether we adopt the hypo- 

 thesis of Shmidt that it results from the union of two proteids, 

 fibrinogen and fibrinoplastic substance, or the latter theory of 

 Hammarsten that fibrin is produced from fibrinogen by the 

 action of a special ferment." 



Professor Barker then considers the function of the nervous 

 system and states that " the nerve-cell and the nerve-fibre are 

 occupied solely in the transmission of energy which is in all 

 probability electrical." The only objection to the electrical 

 character of nerve energy is based upon its slow propagation ; 

 but considering that it has been shown by Weber that animal 

 tissues in general have a conductivity only one fifty-millionth of 



