1885.] 



MICROSCOPICAL JOURNAL. 



209 



variety of conditions and upon a 

 o-reat number of soils ; and so the 

 products ot termentative change must 

 necessarily vary accordingly. Many 

 of them may be poisonous in charac- 

 ter while many others may be in- 

 nocuous. So also it must be with 

 the micro-organisms which are asso- 

 ciated with disease, in consequence 

 of which it follows that so-called zy- 

 mogenic organisms may become pa- 

 thogenic in character — simultaneous- 

 ly with a change of soil or other 

 condition — and vice versa. 



Reviewing all these possibilities 

 and facts, is the science of disinfec- 

 tion to throw overboard all accumu- 

 lated knowledge, experience and 

 faith in the action of all disinfectant 

 substances which are not under all 

 conditions germicidal in property? 

 Is the object of mankind henceforth 

 to be the destruction of micro- 

 organisms? If such an object could 

 possibly be regarded as well founded, 

 even then it were idle to attempt its 

 consummation, for micro-organisms 

 are ubiquitous and constitute a neces- 

 sary order in creation. By acts of 

 hydrolysis, and oxidation carried on 

 upon all dead organic matter by their 

 agency, such substances are resolved 

 into final innocuous products of 

 change, wdiich are essential to the 

 well-being of the higher orders of 

 creation (plants and animals) . 



The fact is, that men always outstep 

 the natural limits of a discovery and 

 jump at conclusions which are not 

 warranted by the results of further in- 

 vestigation. The somewhat sudden 

 discovery of the intimate association 

 of micro-organisms with disease led 

 many to think that, in order to pre- 

 vent the spread of disease, the micro- 

 organisms must be killed wherever 

 met with ; but, now that scientific 

 , investigation has proceeded to a 

 further stage, it is being found that it 

 is not the micro-organisms themselves 

 that are poisonous to man, but the 

 products to which they give rise un- 

 der certain conditions. Those, there- 

 fore, who have the charge of the 



public health must now trim their 

 sails anew, and henceforth the stud} 

 of this matter enters upon a new 

 phase, which is chemical in its char- 

 acter. We must now seek to discover 

 under what conditions and from what 

 substances various micro-organisms 

 elaborate poisonous substances, and 

 also to determine the chemical com- 

 position of these products. 



In the meantime physiologists and 

 microscopists must abandon their old 

 methods of testing disinfectants. It 

 will no longer serve, in order to ascer- 

 tain the value of a disinfectant, to take 

 a particular colony of micro-organ- 

 isms and expose them to the presence 

 of the disinfectant, with the view of 

 ascertaining if they are killed thereby, 

 by means of subsequent attempted 

 isolation and culture ; nor will it 

 sufiice to expose a colony of micro- 

 organisms to the presence of disinfec- 

 tants, and, after isolation, to inoculate 

 animals therewith. On the other 

 hand, the infectants must be intro- 

 duced into the bodies of animals 

 simultaneously with and in the pres- 

 ence of the disinfectant, and if the 

 specific disease do not follow upon 

 the inoculation the disinfectant is a 

 reliable one for that particular set of 

 circumstances. 



After all, then, we fall back upon 

 old lines of policy, and must have 

 recourse to chemical substances which 

 act on the one hand as antiseptics, 

 thereby preventing micro-organisms 

 from multiplying" and producing 

 poisonous substances (real infectants) 

 and substances which by chemical 

 changes, such as oxidation and chlo- 

 rination, act in a destructive sense to 

 the same chemical poisons if they 

 happen to be already in existence. 

 Indeed, the idea of employing some 

 active chemical poisons, such as car- 

 bolic acid, sulphurous anhydride, 

 absolute alcohol, creosote, chlorine 

 and corrosive sublimate for the treat- 

 ment of diseases like cholera, typhoid 

 fever and dysentery is, of course, ab- 

 solutely out of the question : and the 

 only hope is that a non-poisonous 



