NOVY ON BENEFITS OF BACTERIOLOGY. 17 



Antiseptic and aseptic surgery is the pride of medicine, since the prin- 

 ciples laid down by Lister, extended and widened by more recent investi- 

 gations on bacteria have enabled the surgeon to accomplish results and 

 to save life to a degree which otherwise would be impossible. 



Another name must not be forgotten in this connection. Indeed 

 it cannot be forgotten, for wherever there is a mother, consciously 

 or unconsciously she must render her grateful thanks to that 

 benefactor of womankind and of the entire human race, who devoted 

 the best years of his life to free woman from the unnecessary dangers 

 of childbirth. At the recent International Congress of Hygiene, held in 

 Budapest last September, a monument was erected to perpetuate the 

 memory and works of Ignatius Semmelweiss. 



In the antiseptic methods of prevention of infectious diseases which 

 have been alluded to, the attempt is made to prevent the disease by 

 removing the causative organism through rigid cleanliness or by prevent- 

 ing the growth of the organism, or actually destroying it by means of 

 chemical substances or germicides. A knowledge of the means whereby 

 bacteria can be destroyed is of the greatest practical benefit to every 

 person. It is clear that if the organisms can be prevented from growing 

 in the body the disease cannot originate. Quarantine or isolation and dis- 

 infection have these objects in view. The results thus obtained in pre- 

 venting the spread of infectious diseases are only too well known. 



Many of the communicable diseases may be prevented by other means 

 than those outlined. It is a matter of experience that frequently one 

 attack of a disease prevents against a second attack. This fact was 

 recognized 3,000 years ago by the Chinese and utilized to prevent the 

 spread of smallpox. Variolation as practiced in the far East was intro- 

 duced into western Europe not quite 200 years ago. This method of insur- 

 ing protection against the disease was replaced a hundred years ago by the 

 safer and equally efficacious method of vaccination of Jenner. We do not 

 even now at the close of the 19th century know what the cause of 

 smallpox is, yet we are in possession of a perfect means to prevent this 

 dreaded scourge. Vaccination prevents the disease from developing 

 within the body. It confers immunity or freedom from that disease. 



The principle of vaccination was not extended until 14 years ago, when 

 Pasteur in his study of the germ of chicken cholera, observed that after 

 a time it lost its virulence, that it became weakened. The genius within 

 the man at once indicated the practical application of this fact. 

 Vaccination with cowpox protects against smallpox and this was as- 

 sumed to be due to the fact that cowpox was a modified or weakened 

 form of smallpox. Acting on this assumption, Pasteur attempted to 

 vaccinate animals against chicken cholera by first inoculating them 

 with the weakened culture of the chicken cholera bacillus. In this he 

 was successful and perfect immunity to the disease was obtained. Means 

 were discovered by Pasteur for weakening or attenuating other disease 

 organisms and in this way successful vaccinations were made in animals 

 against anthrax, symptomatic anthrax, malignant oedema, hog erysipelas 

 etc. Since then the chemical products of these organisms have been 

 employed with equally successful results in inducing immunity to 

 disease. The means which are now known for producing immunity in 

 animals against infectious diseases are almost too numerous to mention. 

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