488 THE CAUSATION OF PUTREFACTION AND FERMENTATION 



Yet the urine which had so long remained unaltered under the free influence 

 of the gaseous constituents of the atmosphere proved as prone as ever to the 

 usual effects of exposure to the air as soon as particles of dust could gain access 

 to it ; for the wine-glass having been covered to prevent evaporation, I found 

 the fluid in two days with a dunghill odour, and loaded with minute microscopic 

 organisms, and a few days later different kinds of fungi visible to the naked eye 

 were growing in it. 



Gentlemen, I commend these facts to your candid and impartial judgement, 

 beseeching 3^ou to form your own opinions regarding them. The minds which 

 you bring to bear upon this subject to-day are very much the same as they will 

 be throughout your lives. An observation which any one of you ma}^ make 

 now will serve in after life to illustrate a course of lectures, should he occupy a 

 position corresponding to that which I have now the honour to hold. And you 

 are as competent as j^ou ever will be to draw logical inferences from established 

 data. Do not, then, let any authority shake your confidence in knowledge so 

 obtained. 



Throughout the course on which we are entering I shall endeavour, as far 

 as possible, to place before you simple facts — trusting that, in estimating their 

 significance, 3^ou will be ever guided by that which our dear master has so con- 

 stantly striven to inculcate as our leading principle, the love of Truth. 



