derived from reliable sources and the tendency of whose teach- 

 ing was to excite unreasonable alarm. Had those gentlemen 

 to whom we are accustomed to look for enlightenment dealt 

 more fully with this important question, I should not have done 

 more this evening than casually refer to it ; but while it is 

 known that they have been carefully inquiring into it, only one 

 or two have given us the benefit of their investigations. And 

 here I should like to express an opinion that our Society is 

 indebted to Dr. Hirschfeld for having given so great prominence 

 to the science of bacteriology. I do this with much pleasure, 

 because, having ventured to dispute on more than one occasion 

 the reliability of information from which his deductions were 

 made, it would be ungenerous were I not to give him credit foj." 

 desiring to use his knowledge and skill for the public good. It 

 will also be understood that in most instances the statements I 

 venture to make ai-e not derived from personal observation, but 

 from the writings of scientists who have devoted years to the 

 most careful investigation of the life history of what were once 

 called " microbes," but are more commonly referred to now as 

 " bacteria " or " bacilli." 



So far as the general public are concerned, the science of 

 bacteriology unfortunately has come before them almost ex- 

 clusively in connection with the relation of bacteria to disease. 

 Timid persons have shuddered at the idea that disease may be 

 communicated from one victim to another by the agency of 

 microscopic organisms whose presence cannot be detected until 

 they have commenced their often fatal attacks. It does not occur 

 to them that what we have hitherto Imown as infection or con- 

 tagion is the same thing under a less clearly defined name ; nor 

 has it yet come to be understood that very many bacteria work 

 for the good of the human race, and that even those Avhich are 

 noxious are only capable of doing harm when, if I may so express 

 myself, the soil is favourable to their growth. 



During the last few months the disease commonly known 

 as leprosy hasfurnislied a subject which has been greedily seized 

 upon by newspaper correspon.lents ; but, setting aside the 

 evidence of specialists, can it be seriously believed that the danger 

 of infection is so great as many persons have represented ? At 



