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THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



are important differences in regard to the possi- 

 ble independent origin of the two processes which 

 have hitherto been only too much neglected. The 

 treatment of this subject has often been much too 

 superficial. In order to produce a kind of picto- 

 rial effect whicli may easily captivate the imagi- 

 nation, difficulties are often ignored, and many 

 new, modifying, or antagonistic points of view 

 have even of late been treated as though they 

 were non-existent. 



A few words will suffice to make plain some 

 of the differences between the respective condi- 

 tions which would be operative in the germless 

 origin of fermentation on the one hand, and in 

 the de novo origin of a contagious disease on the 

 other. And in so doing I shall be able, I think, 

 at the same time, to show how much simpler it 

 would be to bring about an independent zymosis 

 than an independent fermentation — that is, if we 

 are to rely on the analogy upon which the germ- 

 theorists base their arguments. 



During the great majority of fermentations, 

 living organisms make their appearance and rap- 

 idly multiply. These living organisms have been 

 proved to be common producers of chemical prin- 

 ciples, some of which are soluble ferments, oth- 

 ers (like pyrogen) are poisons which may be al- 

 most as deadly as that of a serpent, while others 

 still are inert and appear as mere pigment-gran- 

 ules. It is proved that some of these chemical 

 principles act as true ferments. 1 It is thought, 

 and it is probable, that the organisms themselves 

 — altogether apart from their media and what 

 else they may contain — may be capable of doing 

 the same. Still this has not yet been definitely 

 proved ; so that the action of soluble chemical 

 ferments is at present almost better substanti- 

 ated than that of the living organisms by whicli 

 they may have been formed. By means of boil- 

 ing alcohol and other agents these bodies can be 

 isolated and freed from living impurity. It is, 

 however, much more difficult entirely to separate 

 minute living organisms from their media, 2 and, 

 consequently, more difficult to be perfectly cer- 

 tain in regard to their potencies. It is, however, 



1 Pasteur, Comptes Eendus, July 3, 1876, p. 4. 



8 The more efficient means of filtering organisms 

 from their media, which we now possess, by mean? of 

 porous earthenware, ought to be useful in this direc- 

 tion. Such organisms and their germs might be sub- 

 sequently washed with several distilled waters, just 

 as a chemist would wash a delicate precipitate. It 

 would be strange, indeed, if this very mild usage inter- 

 fered with the properties of organisms which at other 

 times are credited with such remarkable powers of 

 endurance. 



on account of the derivation of the chemical fer- 

 ments from the living units, and because of the 

 presence of these latter bodies in all fermenting 

 mixtures, that their own agency is still regarded 

 by many as essential to the initiation of ordinary 

 fermentations. But, as I have already indicated, 

 we much need further information as to the pre- 

 cise mode in which fermentation is initiated and 

 carried on by soluble ferments like that which 

 M. Musculus discovered in and separated from 

 urine. If they (all or any of them) are capable 

 of setting up fermentations in germless fluids in 

 the course of which organisms appear, such phe- 

 nomena would most effectually disprove an exclu- 

 sive germ-theory. 



Turning now to the process of zymosis, we 

 find the available generative conditions altogether 

 different. Here we have to do not with fluids 

 only, but with tissues and organs composed of 

 living elements characterized by all kinds and 

 degrees of activity. Some of them produce the 

 various soluble ferments of the body, some may 

 produce poisons, and others habitually lead to 

 the formation of pigment-granules — vital acts 

 severally similar in kind to those which the com- 

 mon ferment-organisms are known to manifest. 

 Tissue-elements without number having such and 

 multitudes of other properties are, therefore, ever 

 present, capable under certain influences of being 

 more or less easily diverted into unhealthy modes 

 of action, so that many of them may become 

 true living ferments in the modern sense of that 

 term, 1 and therefore possible producers of chemi- 

 cal ferments (contagia) capable of initiating some 

 or the whole of the series of changes by which 

 they were themselves produced, in other suitable 

 sites. 



The essential difference between the two prob- 

 lems thus becomes plain. The only point which 

 my experiment leaves in the least doubtful in re- 

 gard to the causal conditions initiating fermenta- 

 tion is, whether any latent, powerless, and, as it 



1 How legitimate this statement is may be seen 

 from what M. Pasteur himself says. These are his 

 most mature views: "I have been gradually led to 

 look upon fermentation as a necessary consequence of 

 the manifestation of life, when that life takes place 

 without the direct combustion due to free oxygen. . . . 

 We may partially see, as a consequence of this theory, 

 that every being, every organ, every cell which lives 

 or continues its life without making use of atmos- 

 pheric air, or which uses it in a manner insufficient 

 for the whole of the phenomena of its own nutrition, 

 must possess the characteristics of a ferment with 

 regard to the substance which is the source of its to- 

 tal or complementary heat."— Comptes Bendus, 1872, t. 

 lxxv., p. 784. 



