506 



THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



What the " different testimony " here spoken of 

 is I do not know, but I do know that the " cloud 

 of witnesses " confront this writer now, as they 

 did in 1876. Save by such intimations as the 

 above, which seem to point to a reserve of wis- 

 dom in the writer's private mind, he has never, 

 to my knowledge, attempted to shake their evi- 

 dence. The birth of the " witnesses " was on this 

 wise: At a meeting of the Pathological Society, 

 especially convened for the discussion of the 

 " germ-theory " of contagious disease, my re- 

 spondent thus addressed his medical colleagues : 



"With the view of settling these questions, 

 therefore, we may carefully prepare an infusion 

 from some animal tissue, be it muscle, kidney, or 

 liver ; we may place it in a flask, whose neck is 

 drawn out and narrowed in the blowpipe-flame ; 

 we may boil the fluid, seal the vessel during ebul- 

 lition, and await the result, as I have often done. 

 After a variable time, the previously-heated fluid 

 ■within the hermetically-sealed flask swarms more 

 or less plentifully with bacteria and allied organ- 

 isms." 



The speaker had already informed his au- 

 dience that he was discussing " a question lying 

 at the root of the most fatal class of diseases to 

 which the human race is liable." Special care, I 

 thought, was needed in the performance of ex- 

 periments which lay at the basis of a subject of 

 this importance. I was not sure that the speaker 

 had observed this care. I therefore took him at 

 his word, prepared infusions of animal tissues, 

 comprising mutton, beef, fowl, wild-duck, par- 

 tridge, plover, pheasant, snipe, rabbit, hare, had- 

 dock, mullet, codfish, sole, and other substances. 

 I placed them in flasks, " with necks narrowed 

 and drawn out in the blowpipe-flame." I boiled 

 the fluids, sealed the vessels during ebullition, 

 and awaited the result. These are the "wit- 

 nesses" of whose evidence my respondent pos- 

 sesses an " interpretation " known, as far as I am 

 aware, only to himself. The fact, as known to 

 me and others, is that the witnesses contradicted 

 his assertion. He had affirmed that they would 

 swarm with bacteria and allied organisms. They 

 distinctly refused to do so. This thing was not 

 done in a corner. One hundred and thirty such 

 flasks were submitted to the scrutiny of the Royal 

 Society in January, 1876, while thirty of them 

 were critically examined by the biological secre- 

 tary of the Society, Prof. Huxley. In one flask, 

 and in one only, a small mycelium was discovered,, 

 and it, as Prof. Huxley remarked at the time, 

 afforded a " dramatic confirmation " of the over- 

 whelming evidence otherwise adduced. In this 



flask, and in it only, a small orifice was discov- 

 ered, through which the infusion could be pro- 

 jected, and by which the germinal matter of the 

 air had had access to the flask. 



My respondent next deals with Liebig's doc- 

 trine of fermentation, regarding which, after some 

 preliminary remarks, he says: "If, then, as Lie- 

 big contended, organic matter in a state of decay 

 is capable of acting as a ferment, and of initiat- 

 ing the common fermentations and putrefactions, 

 there surely can be no error in quoting him in 

 support of such views." Certainly not. Whether 

 organic matter in a state of decay possess the 

 power ascribed to it or not, the writer was per- 

 fectly justified in quoting Liebig; but his justifi- 

 cation ceases when by a twist of logic he seeks to 

 make Liebig's views answerable for his own. He 

 goes on to say : " And if it has also been shown 

 that the appearance and increase of the lowest 

 living particles are always correlative of these pro- 

 cesses, Liebig's view, if it is true at all, must be 

 true for the whole of the processes which are es- 

 sentially included under the term fermentation." 



Such logic is best met by the direct and sim- 

 ple statement of the truth. Matter in decay was, 

 in Liebig's view, matter in a state of molecular 

 disturbance. His vision was concentrated on 

 groups of atoms, or molecules — not on organisms. 

 He pictured, in perfect consistency with his theo- 

 retic sight, the propagation of the disturbance of 

 these groups to other groups of unstable consti- 

 tution. These he figured as shaken asunder by 

 the motion of their agitated neighbors ; the visible 

 concomitant of this molecular breaking up being 

 what we call fermentation. Liebig's idea of a 

 ferment had nothing whatever to do with the 

 doctrine of spontaneous generation. He gave 

 that doctrine no countenance ; he derived from it 

 no aid ; and the attempt of the heterogenist to 

 strengthen his position by amalgamation with 

 Liebig is an attempt to mix together wholly im- 

 miscible things. My respondent quotes not only 

 one, but two celebrated German chemists in his 

 favor. I ventured, a few days ago, to place the 

 foregoing extract from the " reply " before a third 

 distinguished German chemist, who is intimately 

 acquainted with Liebig's views. He had two al- 

 ternative hypotheses to account for it. The first 

 need not be mentioned ; the second ascribed the 

 reasoning of the extract to "mere confusion of 

 mind." 



My respondent continues : 



" The heterogenist, therefore, has perfectly 

 good ground for demanding proofs of error from 

 the germ-theorist, rather than more or less po3- 



