ISlov. 29, 1877] 



NATURE 



87 



During the next year the second question which I had 

 attempted to solve, viz., the influence of temperatures 

 above 100° C, was taken up with much greater complete- 

 ness by Prof. Gscheidlen, ot Breslau. ^ After a rhuini of 

 the proofs already given by his predecessors, that certain 

 fluids are not sterilised by boihng ; and, secondly, that as 

 means of sterilising :uch liquids the action of prolonged 

 exposure and that of increased temperature may be re- 

 garded as complementary to each other, he proceeds to 

 relate his own researches, the purpose of which was 

 rather to fill up defects in the evidence than to establish 

 new conclusions. 



The flasks employed were capable of containing 100 

 cub. ceniims. (three and a half oz.) ; they were charged 

 in the usual way with the turnip-cheese liquid, and exposed 

 for short periods in chloride of calcium baths, of which 

 the strengths were cartfully adjusted so as to obtain 

 the requisite temperatures. It was thereby definitely 

 proved that whereas the germinal matter of Bacteria can 

 stand a temperature of 100° for five or ten mmues it is 

 destroyed by temperatures varying from 105° to i \<f? 



In an appendix to my first paper, published in Nature 

 in the autumn of 1873, I showed that the solution of dif- 

 fusible proteids and carbo-hydrates employed by Prof. 

 Huizinga, of Groningen, in the first of the valuable series 

 of experiments^ published by him, relating to the subject 

 of spontaneous generation, require a temperature above 

 that of ebullition under ordinary pressure to sterilise 

 them. This observation has since been established by 

 Prof. Huizinj^a hmiself on the basis of very carefully made 

 experiments,^ by which he has proved at the same time 

 that the liquids in question are rendered completely 

 incapable ot producing Bacteria without extrinsic con- 

 tamination by exposing them to higher temperature. The 

 only points of difference between us, either as regards 

 method or result, are, first, that the sterilisation limit 

 (Grenze zur Bacierienerzeugung) fixed by me was too 

 low — the true limit being iio" C— and secondly, that the 

 experiments from which I had inferred that the liquids in 

 question had been sterilised at lower temperatures than 

 this were, in Prof. Huizinga's opinion, rendered incon- 

 clusive by the fact that my flasks were sealed hermeti- 



tion notwithstanding that the results obtained were mere confirmations of 

 those ol former observers ; adding "liir den wissenschaftlichen Fortschritt 

 hat nicht die Prioritat des eiuen oder des anderen Beob'.chters, wohl aber 

 die Zahl, Mannigfaltigkeit, und Zuveriassigkeit der beobachiungen eine 

 hohe Wichtigkeit." 



' " Ueber die Abiogenesis Huizinga's," von Richard Gscheidlen, PJluger's 

 Archiv, vol ix p 163 



2 " Es folgt aus den eben angegebene n Versuchen, nach meiner Meinung, 

 dass in Huizinaa's Gemengen die Bacterien einer Teinperatur von 110° 5 10 

 Minuten lang zu widerstehen vermogen, nicht aber emer von io5°-iio"^ in 

 eingeschnioizenem "lasruhre wanrend der namlichen Zeit" (loc. cit. p. 167). 

 Here the author clearly fails to make the nece'ssary distmction between 

 Bacteria (which, as is well known, lose tdeir vitality at a much lower tem- 

 peraiure) and the material out of which they spnng. The mixtures referred 

 to were eiiher the cheese and turnip liquid or solutions containing peptones 

 and grape sugar, to be in.mediat'-ly relerred to. As affording an elegant 

 demonstration that in the turnip-cheese liquid it is the cheese and not any 

 other constituent which contains the resi.>-tant element, the following form of 

 experiment is worthy of notice : — A tube A drawn out and closed at both 

 enCs is fused into the open mouth of a second tube B, of which the opposite 

 end is drawn out and closed in a similar manner. In this way a compound 

 tube is formed wtiich is divided by a conical seotum into two chambers A 

 and B A small knob of gla.ss having been previously introduced into the 

 chamber b, the septum can be easily broken by shaking the tube. With 

 tubes so prepared two experiments are made. In Experiment i, compart- 

 ment A is charged with infusion of cheese, sealed. a.id then exposed to a 

 temperature of 110° before it is united to the compartment B. In like 

 manner B is charged with neutral decoction of turnip, so that when the com- 

 pound tube is complete it coiitams clieese in one compartment, turnip in the 

 other. If. after boiling for ten minutes, it is placed in the warm chamber its 

 contents remain barren. In Experiment 2 the experiment is varied by simply 

 omitting the preliminary heating of A. The compound tube is bailed as 

 before, but now its content.-, promptly give evidence that the conditions are 

 present for an abundant development ui Bacteria. 



3 Prof. Huizinga s papers on tlie Qiirstion of Abiogenesis are four in 

 number. The references are as follows: — PJtiiger's Archiv, vol, vii. p. 225, 

 vol. viii. pp 180, 551 ; vol. x. p. 62 



4 1 he solution employed in these experiments was neutral, and contained, 

 in addition to the requisite inorganic salts, 2 per cent, of g'ape su^ar, o 3 

 per cent, of ioluble starch, 03 per cent, of peptones, and i per cent, of 

 ammonic tartrate. As in my experiments, the fla.sks were heated in a Papin's 

 pot, of which the temperature was 102° C. Even after half an hour's ex- 

 posure to this temperature all the flasks became in two or three days " stark 

 triibe undvoU Bacterien," third paper, p. 555, January, 1874. 



cally, whereas in his exchange of air was allowed to take 

 place during the period of incubation, through a septum 

 of porous porcelain. To this last objection I might per- 

 haps have thought it my duty to answer, had it not been 

 shown by the subsequent researches of Gscheidlen to have 

 no bearing on the question at issue. As regards the limit 

 of sterilisation I can entertain no doubt as to the accuracy 

 of Huizinga's measurements, and am quite willing to 

 accept 108° C. as the lowest temperature which could be 

 safely employed under the conditions laid down by him. 



It will be understood that in bringing these facts before 

 the Society my only purpose is to show, as I trust I have 

 done conclusively, that the statements which Dr. Tyndall 

 in 1876 characterised as incautious, and which he virtually 

 invited me to retract, had been two years before confirmed 

 in every particular by experimenters of acknowledged 

 competence. 



I 



DIFFUSION FIGURES IN LIQUIDS^ 



N making some experiments on the mixture of liquids 

 entering into another liquid at the extremity of a tube 

 of small diameter, a phenomenon presented itself which 

 attracted my attention as both new and singular. A 

 certain quantity of coloured alcohol, remaining in sus- 

 pension in the centre of a body of water, assumed, by 

 spreading gradually out, a form resembling that of a 

 shrub having its trunk and its branches terminated by 

 leaf-Hke expansions. I sought to reproduce the pheno- 



FiG. I. —Apparatus of Prof. Martini. 



menon, believing at first that this mode of diffusion was 

 purely accidental ; but the phenomenon always recurring 

 very nearly in the same manner, I devised a mode of 

 experimenting which enabled me to study it more 

 advantageously. 



C (Fig. i) is a sort of cylindrical funnel of glass, to the 

 neck of which is fitted a small capillary thermometrical 

 tube T, about eight centimetres long. The capillary tube 

 communicates by means of a caoutchouc tube a by with a 



» From an article in La Nature by Prot Tito Martini, of Venice. 



