THE CONQUEST OF DISEASE 



cause the functions of the different parts of the 

 brain have been worked out, and the location 

 of disease is now determined by its interfer- 

 ence with these functions. Tumors, hemor- 

 rhages, obscure compressing-bone-fragments, 

 and foreign bodies can now be localized. Op- 

 erations for the relief of these conditions are 

 common occurrences, and are made possible 

 and successful by virtue of these experiments. 

 Such operations were utterly impossible be- 

 fore brain localization was studied upon ani- 

 mals. Not all brain tumors are amenable to 

 surgical treatment. The disease untreated is 

 fatal. Out of 440 reported cases treated by 

 operation 186 have resulted successfully. This 

 is still a high percentage of failures, but it rep- 

 resents 186 persons saved. 



Blood The surgery of the blood vessels has been 



vessels. aided by these means. Studies of the ef- 



fects of ligatures upon blood vessels were 

 practised on dogs ; and every day, surgical pa- 

 tients are enjoying the benefits accruing there- 

 from. Prior to the year 1785 the best known 

 treatment for aneurism consisted in exposing 

 the aneurism and tying the vessel in the wound. 

 The operation was frequently unsuccessful 

 owing to fatal secondary hemorrhage. John 



