176 Royal Society : — 



tian's mode of treating turnip and cheese so as to obtain phenomena 

 supposed to be in favour of the doctrine of Archebiosis, we consider 

 that the importance of exchiding visible lumps from the experi- 

 mental infusions is clearly indicated, as also is the comparatively 

 greater trustworthiness of the small tube as opposed to the larger 

 retort for use as an experimental vessel. We moreover consider 

 that we, in our earlier experiments (November and December), 

 carefully following Dr. Bastian's directions, as far as he had given 

 any in the ' Beginnings of Life,' but using at the same time proper 

 care as to cleanliness and due boihng, obtained a series of results 

 contradicting Dr. Bastian's statements as to the spontaneous genera- 

 tion of Bacti'ria in iufusiou of turnip to which a fragment of cheese 

 had been added. 



Further, certain of the experiments above recorded, and others 

 made at the same times with open vessels and simple turnip-infu- 

 sion, compel us to dissent emphatically from the conclusion of the 

 following statement contained in a recent paper by Dr. Bastian 

 ('Nature,' Feb. 6th, p. 275): — " Taking such a fluid, therefore, in 

 the form of a strong filtered infusion of turnip, we may place it 

 after ebullition in a superheated flask, with the assurance that it 

 contains no living organisms. Having ascertained also, by our 

 previous experiments with the boiled saline fluids, that there is no 

 danger of infection by Bacteria from the atmosphere, we may leave 

 the rather narrow mouth of the flask open, as we did in these 

 experiments. But when this is done, the previously clear turnip- 

 infusion invariably becomes turbid in one or two days (the tem- 

 perature being about 70° F.), owing to the presence of myriads of 

 Bacteria." The italics are our own. 



We find not only that such an infusion remains free from 

 Bacteria when thus treated (subject, of course, to certain failures in 

 the precautions taken) for " one or two days," but if contamination 

 by the admission of coarse atmospheric particles capable of carry- 

 ing Bactena be guarded against, it will remain so for weeks and 

 probably for years. In consequence of this absence of develop- 

 ment of Bacteria we have cultivated Torulce in such a turnip- 

 infusion, so as to obtain them entirely free from the former 

 organisms*. 



In conclusion, we would point out that failure in manipulation, 

 contamination in unsuspected ways, such as that due to the pre- 

 servative influence of lumps, and, again, the mistaking of particles 

 in an infusion which have been there from the first for organisms 

 originated de novo, do not exhaust the Ust of conceivable explana- 

 tions of phenomena which have been attributed to spontaneous 

 generation. When the knowledge of the natural history of Bacteria 

 has advanced somewhat further, there will be a possibility of such 

 explanations presenting themselves in ways at this moment un- 

 suspected. 



* At this moment, May 20th, the turnip-infusion in the open retort (No. 41) 

 is free from all organisms, and is perfectly limpid and sweet. 



