1873.] Dr. H. C. Bastian on the Origin of Bacteria. 129 



January 30, 1873. 

 GEORGE BUSK, Esq., Vice-President, in the Chair. 



The following communications were read : — 



I. " Note on the Origin of Bacteria, and on their Relation to the 

 Process of Putrefaction." By H. Charlton Bastian, M.D., 

 F.R.S. Received November 20, 1872. 



In his now celebrated memoir of 1862, M. Pasteur asserted and claimed 

 to have proved (1) that the putrefaction occurring in certain previously- 

 boiled fluids after exposure to the air was due to the contamination of 

 the fluids by Bacteria, or their germs, which had before existed in the at- 

 mosphere, and (2) that all the organisms found in such fluids have been 

 derived more or less immediately from the reproduction of germs which 

 formerly existed in the atmosphere. 



The results of a long series of experiments have convinced me that both 

 these views are untenable. 



In the first place, it can be easily shown that living Bacteria, or their 

 germs, exist very sparingly in the atmosphere, and that solutions capable 

 of putrefying are not commonly infected from this source. 



It has now been very definitely ascertained that certain fluids exist 

 which, after they have been boiled, are incapable of giving birth to Bac- 

 teria, although they continue to be quite suitable for the support and 

 active multiplication of any such organisms as may have been purposely 

 added to them. Amongst such fluids I may name that now commonly 

 known as " Pasteur's solution," and also one which I have myself more 

 commonly used, consisting of a simple aqueous solution of neutral am- 

 nionic tartrate and neutral sodic sulphate*. When portions of either 

 of these fluids are boiled and poured into superheated flasks, they will 

 continue quite clear for many days, or even for weeks — that is to say, 

 although the short and rather narrow neck of the flask remains open the 

 fluids will not become turbid, and no Bacteria are to be discovered when 

 they are submitted to microscopical examination. 



But' in order to show that such fluids are still thoroughly favourable 

 media for the multiplication of Bacteria, all that is necessary is to bring 

 either of them into contact with a glass rod previously dipped into a fluid 

 containing such organisms. In about thirty-six hours after this has been 

 done (the temperature being about 80° P.), the fluid, which had hitherto 

 remained clear, becomes quite turbid, and is found, on examination with 

 the microscope, to be swarming with Bacteria f . 



Pacts of the same kind have also been shown by Dr. Burdon Sander- 



* In the proportion of 10 grains of the former and 3 of the latter to 1 ounce of 

 distilled water. 



f The Modes of Origin of Lowest Organisms, 1871, pp. 30, 51. 



