682 THE POPULAR SCIENCE MONTHLY. 



Among the labors of the present generation, none perhaps have 

 already more far-reaching results, none hold out more promise of fruit 

 in the future, than those which bear on the influence of the nervous 

 system over the circulation of the blood and over nutrition. The 

 knowledge we are gradually acquiring of the subtile nervous bonds 

 which bind together the unconscious members of the animal common- 

 wealth, which make each part or organ at once the slave and guar- 

 dian of every other, and which with cords of nervous sympathy draw 

 each moiety of the body to work for the good of all, is putting a new 

 aspect on physiology, and throwing many a gleam of light into the 

 very darkest regions of the science. The words " inflammation " and 

 " fever," bandied about of old as mystery-words, sounding much but 

 signifying little — shuttlecocks tossed to and fro from one school of doc- 

 trinaire pathologists to another — now at last, through the labors of mod- 

 ern physiology, seem in a fair way of being understood. That under- 

 standing, when it is complete, will have been gained step by step 

 through experiments on living animals, one of the first of which was 

 Claude Bernard's research on vaso-motor nerves. 1 



There still Remains the question, What good does physiology bring 

 to mankind? Of the value of physiology as a not insignificant seg- 

 ment of the circle of universal knowledge, nothing need be said ; 

 where saying aught is necessary, it would be useless. Nor need much 

 be said concerning the practical value of physiology as a basis for the 

 conduct of life. So long as men refuse to learn or to listen to physi- 

 ology in order that they may the better use their bodies, it would be 

 hopeless and useless to talk of the day when they may come to it for 

 instruction how to form their minds and mould their natures. It will 

 be enough for my present purpose to point out briefly the relations of 

 physiology to the practical art of medicine. 



These are twofold. In the first place, the medical profession is 

 largely indebted to physiology on account of special discoveries and 

 particular experimental researches. If we regard the profession sim- 

 ply as a body of men who possess or should possess a remedy for 

 every disease, this may seem an exaggerated statement. Many of the 

 remedies in use or in vogue at the present day have been discovered 

 by chance, borrowed from ignorant savages, or lighted on by blind 

 trials. Physiology can lay no claim to the introduction of opium or 

 quinine. Where specific remedies have been suggested by physiologi- 



1 The great importance of the vaso-motor system justly led Mr. Huxley to introduce 

 into his " Elementary Lessons in Physiology " Bernard's fundamental experiment with 

 some such words as " a rabbit may be made to blush artificially by dividing the sympa- 

 thetic nerve." A writer, apparently biased by the memories of his own boyhood, has 

 accused Mr. Huxley of thereby dangerously inciting boys and girls to cruelty, as if the 

 division of the sympathetic nerve were the sort of thing a school-boy might do with a 

 pocket-knife and a bit of string. Is it any use to enlighten the malevolent ignorance of 

 such minds by telling them that many physiological experiments require such skill and 

 care as make ordinary surgical operations seem rough and easy proceedings ? 



