[ 17 ] 

 By Mrs. Alice Eodington. 



N a scientific journal an apology is hardly needed 

 for introducing this most interesting subject to the 

 reader, though the field which it covers is so vast 

 that only a small portion of it can be treated in one 

 paper. All who have followed, however imper" 

 fectly, the patient and laborious researches of the 

 great scientists, who have given up their lives to 

 the study of micro-organisms in disease, all such 

 students know how fascinating it has been to watch 

 the flood of light which has been poured over some of the darkest 

 secrets of medicine. It is, perhaps, not too much to say, that these 

 researches into the part played by micro-organisms in disease have 

 laid the very foundations for a science as distinguished from the art 

 of medicine. Formerly, when men spoke of infection, they spoke of 

 they knew not what, they combated they knew not what, and often, 

 as in the exhaustive bleedings practised in fevers, they actively aided 

 the enemy they sought to destroy. Now, the microscopically minute 

 foe is being hunted out, his whole life-history in many cases made 

 known, and the most efficient means devised for expelling and 

 exterminating him. Medicine has no longer to grapple with an 

 unknown and invisible foe. 



I will now attempt to give a brief history of a few pathogenic 

 micro-organisms, and of the diseases to which they give rise. I 

 propose to divide these micro-organisms into two classes : first, 

 those which having entered the human body are ineradicable, and 

 the only end to whose ravages is death ; secondly, those which 

 keep up a warfare in our systems, and either destroy or are destroyed. 

 Foremost in the first class, both with regard to its historical im- 

 portance and the extent of its ravages, stands Bacillus Leprae. 



Of all the terrible diseases which have afflicted mankind, no 

 one has been so universally dreaded as leprosy. Though the con- 

 tagiousness of this disease has lately been considered doubtful, yet 

 its horrible and incurable charactermade the possibility of contagion 

 New Series. Vol. I. c 



1888. 



