SP ONTANEO US GENERA TION. 



117 



enough to exclude them, is not apparent. Neither 

 is it quite obvious why the red-hot platinum, which 

 would burn up all the germs in ordinary air, should 

 fail to do so when the contamination was exces- 

 sive. And we are not quite sure that the subsi- 

 dence of small particles from the air is at all hin- 

 dered by increasing their number ; and if it were, 

 it would not be a very serious matter to an ob- 

 server furnished, as Prof. Tyndall is, with an op- 

 tical method of testing the purity of air so deli- 

 cate as to determine the instant when the last 

 particle of germinal or other matter has deposited 

 itself. Even when these difficulties are got over, 

 there is no warrant that we know of for assuming 

 that old dry hay will fill the air with swarms of 

 bacterium-germs. On the contrary, everything 

 at present rather points to the hypothesis that 

 desiccation would be fatal to bacteria and their 

 germs, if they have any. No doubt it is true, as 

 the professor pointed out, that hard, dry seeds 

 will stand an amount of heat which would utterly 

 destroy them when they were once soaked through. 

 Many persons would probably be able to confirm 

 his experience, that a very dry pea may be boiled 

 for hours before the moisture penetrates its hard 

 coating ; and it is common knowledge now that 

 a considerable amount of dry heat will not de- 

 stroy the power of germination in seeds, which 

 would yield at once to a moist temperature much 

 below the boiling-point. Boiling a pea, therefore, 

 seems a scarcely conclusive proof that bacterial 

 germs, if there are any, can survive desiccation 

 and induration, that they are freely given off in 

 this protected state from old hay, and that when 

 they get into the air they have a special power, 

 not possessed by their moister brethren, of re- 

 sisting subsidence, penetrating cotton-wool, and 

 enduring the contact of air calcined by red-hot 

 platinum. All this may be worked out some day, 

 but it will need something more than boiled peas 

 or dried seeds to establish it. The true inference 

 to be drawn from the two series of experiments 

 seems to be that the discrepancy has arisen from 

 some cause which neither the public nor the pro- 

 fessor himself have as yet any trustworthy means 

 of so much as guessing at. The wise course would 

 be to abandon for the future the unsatisfactory 

 and complicated machinery employed in Prof. 

 Tyndall's mode of experimentation, and to resort 

 to simpler means of excluding atmospheric dust ; 

 and as to the conflicting experiments of 18*76 to 

 1877, to let them drop quietly out of the argu- 

 ment until explained, the more especially as, in 

 the case of neutral or slightly alkaline fluids, 

 many of them contradict the orthodox germ-the- 



orist, Pasteur, quite as emphatically as they do 

 such heretics as Bastian and Huitzinga, to say 

 nothing of the mysterious Dr. Sanderson, whom 

 we dare not class either among the orthodox or 

 the unbelievers, but who, whatever his theories 

 may be, has borne manly testimony to the facts 

 which he has observed. 



A very much more important statement is con- 

 tained in the paper in the " Philosophical Trans- 

 actions of 1876," into which Prof. Tyndall ex- 

 panded his lecture of that year. There it is dis- 

 tinctly, though briefly, alleged that Prof. Tyndall 

 has repeated the Bastian-Sanderson process, and 

 that with purely liquid infusions he found in mul- 

 tiplied experiments that they remained uniformly 

 barren. His own explanation last year was that 

 Dr. Bastian had allowed the gravest errors to in- 

 vade his experimental work ; that the life to which 

 Dr. Sanderson testified, in the case of the purely 

 liquid infusions, arose from errors of manipula- 

 tion ; and this year he adds that even the cele- 

 brated Prof. Cohn appears to have no adequate 

 notion of the care necessary to be taken in ex- 

 periments of this kind. To be consistent he 

 ought to have attributed the same carelessness 

 to Pasteur when he obtained life in boiled neu- 

 tralized fluids, a feat which Prof. Tyndall declares 

 impossible when due precautions are used ; and 

 perhaps in some degree even to himself, for over- 

 looking the possible malignant influence of old 

 hay. The worst of this kind of reasoning is not 

 merely that it may be resorted to on one side as 

 well as on the other, but that it tends to restore 

 the habit of thought which once kept science 

 dead for many centuries — the habit of appealing 

 to authority in place of facts. Prof. Tyndall may 

 or may not ultimately prove to be on the right 

 side, but we crave some other reason for it than 

 the mere assertion that his undoubtedly high au- 

 thority as an experimentalist (backed by Pasteur 

 as to part of his experiments and contradicted 

 by him as to the rest) entitles him to treat with 

 contempt the counter-authority of Bastian, San- 

 derson, Huitzinga, and Cohn. 



At present the case stands thus : The same 

 experiment has been performed by many compe- 

 tent and well-known men, and, strangely enough, 

 with discordant results. Would not the natural 

 solution to such a difficulty be for them to work, 

 as Dr. Sanderson and Dr. Bastian. did, together, 

 and let the world know the result, rather than to 

 hold aloof in barren self-assertion ? This simple 

 course would reveal at once the as yet undetected 

 variations in manipulation which must lie at the 

 root of discrepant results, and one necessary step 



