1873.] 



of Bacteria in Organic Infusions. 



357 



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

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

 contradicting Dr. Bastian's statements as to the spontaneous generation of 

 Bacteria in infusion 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 -infusion, 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 experi- 

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

 invariably becomes turbid in one or two days (the temperature 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 carrying Bacteria be guarded 

 against, it will remain so for weeks and probably so for years. In con- 

 sequence of this absence of development 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, con- 

 tamination in unsuspected ways, such as that due to the preservative 

 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 fist of conceivable explanations 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 unsuspected. 



Whilst awaiting Professor Huizinga's fuller account of his experi- 

 ments, we may point out that the hypothesis of an inhibitory influence of 

 increased density should be supported by experimental evidence, and that 

 it cannot apply to tubes closed before boiling. The neck of the flask 

 closed with asphalt may (so far as conditions are stated by him at 

 present) harbour Bacteria, as in our Series F. But especially we would 

 urge upon him and others that it is undesirable, as yet, to introduce into 



* 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. 



VOL. XII. 2 G 



