CHAP. Vni. MUSC0LAB AND NERVOUS TISSUES. 81 



during the act of nutrition, it is reasonable to suppose 

 that the removal of the blood from the limb might 

 perhaps prevent them from being manifested. I was 

 now led to the following experiments : 



The animals — guinea-pigs, rabbits, and frogs — 

 were bled to death, and the limbs and muscles 

 then emptied, as far as possible, of the blood, by 

 squeezing the limbs ; under these circumstances the 

 muscular and nerve currents were obtained. The 

 amount of deflection was not perhaps so great as it 

 would have been had the blood not been removed ; 

 nevertheless, the current was manifested. I en- 

 deavoured to remove the blood by injecting water 

 (at the temperature of 90° in the guinea-pigs and 

 rabbits, and at the temperature of the atmosphere 

 for the frogs) into the blood-vessels ; and although 

 the water escaped by the veins, still the current was 

 obtained, amounting from S° to 5° in the muscles, 

 and from 1° to 3° in the nerves. The muscles in 

 these latter experiments became turgid, but they 

 were not so pale as might have been expecte4; 

 and I very much doubt whether the blood was 

 entirely removed from the limb or the muscular and 

 the nerve tissue. These latter experiments, as far as 

 they go, would tend to shew the importance and 

 dependence of the current upon nutrition ; and al- 

 though, in absence of further evidence, it would be 

 impossible for us at present to state, or even con- 

 jecture, the period at which the act of nutrition ter- 

 minates, there nevertheless appears to be a residual 



