Comparative Physiology. 349 



is said to have drawn the inference, that the circulation of the 

 blood in man was owing to electricity collecting in the brain, 

 and dischai'ging itself at regular intervals along the nerves con- 

 ducting to the heart. Dr. Carpenter, however, seems to doubt if 

 such opinions be tenable ; and Liebig says there is no ground 

 for them. At page 261., however, he says: " still, as a current 

 of electricity (or a magnet, which produces a current of the same) 

 acts medicinally, causing motion and change, it cannot be con- 

 sidered inefficient." Mliller says : " Neither Person nor he has 

 been able to detect electric currents in the nerves. Pouillet 

 thought the electricity detected by needles was owing to ox- 

 idation of the steel ; as needles of platina, gold, or silver did not 

 give the same indication. Matteucci has seen a deviation of 

 fifteen to twenty degrees in the needle when the liver and 

 stomach of tlie rabbit were connected, which might be owing to 

 different states of electricity. In the nerves themselves Mat- 

 teucci could detect no electric action ; but neither was the gal- 

 vanometer affected when the current of a galvanic battery Avas 

 passed through the nerves. Bellingeri concluded from expe- 

 riments, that in inflamed blood electricity is diminished, and 

 that blood retains its electricity long after it has been abstracted 

 from the body ; but the real existence of free electricity in the 

 blood generally has yet to be proved. Dutrochet's imagined 

 formation of muscular fibre from the blood, by the agency of 

 electricity, has been shown to be an error. Pouillet, in his 

 experiments on the developement of electricity during vegetation, 

 found that vitreous electricity was detected in the gases formed, 

 while resinous electricity was accumulated in the vessels they 

 were growing in." There seems very great difficulty in ar- 

 riving at perfect conclusive opinions on this subject ; as the 

 chemical transformations of the living body are always attended 

 Avith disturbances of electricity, so, likely, will a highly electric 

 state of the atmosphere react on the vital functions. In a moist 

 state of the atmosphere, wliich in that case has a greater con- 

 ducting power, the body feels more cool and relaxed, probably 

 from its greater negative state ; in a dry state of the atmo- 

 sphere, the body feels oppressed from the accumulation producing 

 a positively electrical state, probably acting injui'iously from 

 excess. Some have thought they could detect the presence of 

 galvanic currents in the body, from a magnet being deflected 

 when held near a part of the body. Galvanic currents of elec- 

 tricity are generally thought to pervade all matter, and to be 

 the cause of the magnetism of the earth, and of the formation 

 of metallic veins. The metallic saline substances pervading all 

 plants should attract and increase the conducting power of 

 electric currents, and further the intensity of vital actions : as 

 vital chemical changes develope electricity, so, likely, will our- 

 3a Ser.— 1843. VII. a a 



