MICROSCOPIC ORGANISMS CAUSES OF DISEASE. 21 



important results in Surgery. One reason why com- 

 pound fractures are so dangerous is because, the skin 

 being broken, the air obtains access to the wound, 

 bringing with it innumerable germs, which too often 

 set up putrefying action. Lister first made a practical 

 application of these observations. He set himself to 

 find some substance capable of killing the germs with- 

 out being itself too potent a caustic, and he found that 

 dilute carbolic acid fulfilled these conditions. This 

 discovery has enabled many operations to be per- 

 formed which would previously have been almost hope- 

 less. 



The same idea seems destined to prove as useful in 

 Medicine as in Surgery. There is great reason to sup- 

 pose that many diseases, especially those of a zymotic 

 character, have their origin in the germs of special 

 organisms. We know that fevers run a certain definite 

 course. The parasitic organisms are at first few, but 

 gradually multiply at the expense of the patient, and 

 then die out again. Indeed, it seems to be thoroughly 

 established that many diseases are due to the excessive 

 multiplication of microscopic organisms, and we are not 

 without hope that means will be discovered by which, 

 without injury to the patient, these terrible, though 

 minute, enemies may be destroyed, and the disease thus 

 stayed. Bacillus anthracis, for instance, is now known 

 to be the cause of splenic fever, which is so fatal to 

 cattle, and is also communicable to man. At Bradford, 

 for instance, it is only too well known as the wool - 

 sorter's disease. If, however, matter containing the 

 Bacillus be treated in a particular manner, and cattle 

 be then inoculated with it, they are found to acquire an 



