CONDITIONS FAVOUEING FERMENTATION. 83 



IX. Bearmg of the Experimental Evidence wpon the Germ Theory 



of Disease. 



Thougli it may be conceded that with our present state of 

 knowledge an affirmative decision in regard to the absolute proof 

 of the present occurrence of Archebiosis may be still withheld, there 

 is, I think, no similar warrant for suspense of judgment in regard 

 to the Grerm Theory of Disease or, as it is also called, the doctrine 

 of Contagium Yivum. Existing evidence seems to me abundantly 

 sufficient for the rejection of this doctrine as untrue *. 



My urine and potash experiments will go far to illustrate this 

 difierence in the weight of the evidence in regard to the two 

 questions. 



A "sterilized" fluid — that is, one which left to itself would always 

 remain pure — may be caused to ferment by the addition of a certain 

 proportion of liquor potassae devoid of all living things, especially 

 if the influence of the potash be favoured by certain accessory 

 physical conditions. This fact is admitted by M. Pasteur himself t. 

 During the fermentation thus initiated, a matter (ferment) ap^ 

 pears and increases, which is capable of spreading a similar process 

 far and wide in suitable media. 



But, on the strength of the analogy upon which the germ- 

 theorists rely, we may find in such an experiment a warrant 

 for the belief that in a healthy person, free from the contagium of 

 typhoid fever or any other of its class, certain kinds of ingesta 

 (solids or fluids), wholly free from all specific poison may, 



* Since this paper was read, the doctrine has again been proclaimed — 

 and never with more force and ability — by Dr. William Roberts (Brit. Med. 

 Journal, Aug. 11, 1877). Its essential points may be stated in the words of its 

 latest exponent. He says : — " I have already directed your attention to the 

 analogy between the action of an organised ferment and a contagious fever. The 

 analogy is probably real, in so far, at least, that it leads us to the inference 

 that contagium, like a ferment, is something that is alive. ... If, then, the 

 doctrine of a contagium vivum be true, we are almost forced to the conclusion 

 that contagium consists (at least in the immense majority of cases) of an inde- 

 pendent organism or parasite; and it is in tliis sense alone that I shall consider 

 the doctrine, .... it is more than probable, looking to the general analogy 

 between them, that all infective diseases conform in some fashion to one funda- 

 mental type. If septic Bacteria are the cause of septicaemia, if the Spirilla are 

 the cause of relapsing fever, if the Bacillus anthracis is the cause of splenic fever, 

 the inference is almost irresistible that other analogous organisms are the cause 

 of other infective inflammations and of other specific fevers." — Sept. 1877. 



t See p. 31, note t. 



6* 



