424 Dr. J. B. Sanderson on the Attributes of [Nov. 22, 



ness of the liquid to produce Bacteria can be diminished either by in- 

 creasing the temperature employed to sterilize it, or, if the ordinary 

 temperature of ebullition be used, by prolonging its duration. 



I did not think it necessary since 1873 to occupy myself further with 

 the subject for two reasons : — first, that I had accomplished my object, 

 which was to show that, as a ground for believing in spontaneous genera- 

 tion, the turnip-cheese experiment was a failure ; but secondly, and 

 principally, because in the mean time the subject had been taken up by 

 the most competent living observers, who had in every particular con- 

 firmed the accuracy of my results. I conclude this paper by referring 

 shortly to some of these researches. 



The first was made by P. Samuelson under the direction of Prof. 

 Pfiiiger* in 1873. Its purpose was to ascertain whether it is true that 

 certain liquids can be boiled for ten minutes without being sterilized, 

 and, secondly, to determine the influence of prolonged periods of ex- 

 posure. The flasks employed were charged with the neutral turnip- 

 cheese liquid, and sealed while boiling in the way already described. 

 Some were subjected to the temperature of ebullition for ten minutes, 

 the rest for an hour, the result being that whereas those heated for the 

 longer periods remained without exception barren, an exposure of only 

 ten minutes was followed, in the majority of cases, by an abundant de- 

 velopment of Bacterial. At about the same period a similar series of 

 experiments was made under the direction of Prof. Hoppe-Seyler at 

 Strasburg. The results were essentially the same+. 



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 completeness by Prof . Gscheidlen, of Breslau§. After a 

 resume of the proofs already given by his predecessors, that certain fluids 

 are not sterilized by boiling, and, secondly, that as means of sterilizing 



* "Ueber Abiogenesis, von Paul Samuelson aus Konigsberg," Pfliiger's Archiv, vol. 



viii. p. 277. The paper is designated as a report of experiments made "ini Auftrag 

 und unter der Leitung des Geh.-Eath Professor Pfliiger." I refer in the text only to 

 those experiments which were virtually repetitions of my own. The research actually 

 extended over a wider field. 



t "Als Kesultat dieser Versuchsreihe, ergab sich eine massenhafte Entwickelung von 

 Bacterien in den meisten nur 10 Minuten lang gekochten Fliissigkeitsinengen nach 

 3-4 Tagen" (loc. cit. p. 283). 



\ "Ueber' die Abiogenesis Huizinga's, von Felix Putzeys, aus Liittich (aus dem 

 chemisch-physiologischen Laboratorium des Herrn Prof. Hoppe-Seyler),'' Pfliiger's 

 Archiv, vol. ix. p. 391. In a note appended by Prof. Hoppe-Seyler to this paper he 

 states that he has recommended its publication notwithstanding that the results ob- 

 tained were mere confirmations of those of former observers, adding " fur den wissen- 

 sehaftlichen Fortschritt hat nicht die Prioritat des einen oder des anderen Beo- 

 bachters, wohl aber die Zahl, Mannigfaltigkeit, und Zuverlassigkeit der Beobachtungen 

 eine hohe Wichtigkeit." 



§ "Ueber die Abiogenesis Huizinga's, von Richard Gscheidlen," Pfliiger's Archiv, vol. 



ix. p. 163. 



