42 THE FLOATING-MATTER OF THE AIR. 



upon it, would favour the idea of their vital origin. For 

 if the seeds of contagious disease be themselves living 

 things, it may be difficult to destroy either them or their 

 progeny, without involving their living habitat in the 

 same destruction. 



It has been said, and it is sure to be repeated, that 

 I am quitting my own metier, in speaking of these 

 things. Not so. I am dealing with a question on which 

 minds accustomed to weigh the value of experimental 

 evidence are alone competent to decide, and regarding 

 which, in its present condition, minds so trained are as 

 capable of forming an opinion as regarding the pheno- 

 mena of magnetism or radiant heat. ' The germ theory 

 of disease,' it has been said, ' appertains to the biologist 

 and the physician.' Where, I would ask in reply, is the 

 biologist or physician, whose researches, in connection 

 with this subject, could for one instant be compared to 

 those of the chemist Pasteur ? It is not the philosophic 

 members of the medical profession who are dull to the 

 reception of truth not originated within the pale of the 

 profession itself. I cannot better conclude this portion 

 of my story than by reading to you an extract from a 

 letter addressed to me some time ago by Dr. William 

 Budd, of Clifton, to whose insight and energy the tpwn 

 of Bristol owes so much in the way of sanitary improve- 

 ment. 



' As to the germ theory itself,' writes Dr. Budd, 

 ' that is a matter on which I have long since made up 

 my mind. From the day when I first began to think of 

 these subjects I have never had a doubt that the specific 

 cause of contagious fevers must l)e living organisms. 



' It is impossible, in fact, to make any statement 

 bearing upon the essence or distinctive characters of 

 these fevers, without using terms which are of all others 

 the moat diatinctive of life. Take up the writings of 



