CHAP. xiv. POPULAR DISCOVERIES IN PHYSIOLOGY. 149 



sues will rapidly heal, while dead animal matter can be 

 preserved unchanged almost indefinitely. In the case 

 of wounds and surgical operations this is effected by 

 means of a weak solution of corrosive-sublimate, in 

 which all instruments and everything that comes in con- 

 tact with the wound are washed, and by filling the air 

 around the part operated on with a copious spray of car- 

 bolic acid. Cold has a similar effect in preserving meat; 

 while the process of tinning various kinds of food de- 

 pends for its success on the same principle, of first kill- 

 ing all bacteria or other germs by heating the filled tins 

 above the boiling point, and then keeping out fresh 

 germs by air-tight fastening. 



The combined use of anaesthetics and antiseptics has 

 almost robbed the surgeon's knife of its terrors, and has 

 enabled the most deeply-seated organs to be laid open 

 and operated upon with success. As a result, more lives 

 are probably now saved by surgery than by any other 

 branch of medicine, since in the treatment of disease 

 there has been comparatively small progress except by 

 trusting more to the healing powers of nature, aided by 

 rest, warmth, pure air, wholesome food, and as few drugs 

 as possible. 



