334 



Prof. II. C. Bastian on the Heat 



Nature of Fluids. Nature of Results. 



G-. Weak or strongly acid infusions, and May remain permanently barren, and 



also many saline solutions containing or- never show any traces of organisms, 



ganic impurities. either dead or living *. 



II. To the second subclass belong fluids which, after ^ expo sure to a 

 temperature of 212° F. or higher, may be kept clear or apparently un- 

 altered so long as they are shut off from contact with unheated atmo- 

 spheric or other organic particles, but which, do undergo putrefaction, or 

 more or less marked fermentation, soon after they are brought into con- 

 tact even with mere not-living organic matter. 



The experiments recorded in this communication hare most conclu- 

 sively proved the efficacy of not-living organic matter as a ferment or 

 inciter of change in previously barren fluids. And combining the know- 

 ledge derived from these experiments with that which we now possess 

 concerning the absence of living Bacteria, Vibriones, and their germs in 

 the air, together with the known prevalence of minute organic particles 

 and fragments of various kinds, the explanation of M. Pasteur's cele- 

 brated experiments in which he had recourse to an " ensemencement 

 des poussieres qui existent en suspension dans Fair," becomes quite easy 

 and legitimate without having recourse to the hypothesis of Pan- 

 sperinismf. Now, also, are we enabled to understand all the apparent 

 inconsistencies of those experiments in which previously boiled fluids 

 have been exposed to the ordinary air of different localities, and have then 

 been resealed. If many specimens of these fluids remained unchanged, 

 whilst others, after a few days, swarmed with Bacteria and Vibriones, we 

 may now very safely attribute these previously puzzling results to the 

 comparative absence or presence of organic fragments in the particular 

 volumes of air which chanced to get into the flasks, and to the different 

 nature of the fluids employed by different experimenters J. 



* See many negative experiments recorded in ' The Beginnings of Life,' vol. i. ch. xi. 

 Mr. W. N. Hartley has laboured very industriously to disprove something which I 

 never asserted (see Proceedings of Eoyal Society, vol. xx. p. 140). In my early paper in 

 ' Nature ' I expressly stated that organic impurities were always present in the saline solu- 

 tions which I employed ; and, as may be seen by the note appended to the conclusions of 

 that paper, I never claimed to have established that living organisms could appear in 

 saline solutions free from traces of organic impurity. Mr. Hartley did attempt to work 

 with approximately pure saline solutions, and in other respects also the conditions of his 

 experiments differed so much from mine, that the results which he obtained could not 

 possibly be considered to disprove what I had previously stated. Some of his flasks were 

 heated to 180° C, a temperature about which I had said nothing ; and whilst his organic 

 infusions were too weak, some of his saline solutions were too concentrated, though the 

 strengths of others were not given at all. Fluids were also employed (such as urine, 

 heated to 130° C.) which I had not made use of, and which I should not have thought 

 of experimenting with. 



t See the experiments before alluded to, which are recorded in chaps, iv. & v. of 

 his Memoir. 



| See M. Pasteur's Memoir, chap, vii., and also Compt. Eend. Nov. 5, 1860. See 



