PUTEEFACTION AND INFECTION. 55 



sion was then carefully filtered, and introduced into the 

 six test-tubes by a pipette which was never removed 

 from the case. 



The mutton-juice was of a fine ruby colour ; but on 

 boiling, its albumen was precipitated, subsequently sank, 

 and carried the colouring-matter with it. The superna- 

 tant liquid was perfectly clear. The frothing was con- 

 siderable when the boiling began. Beside this new case 

 was placed a stand containing six test-tubes filled with 

 the same infusion, but exposed to the common air. 



On the 27th all the outside flasks were perceptibly 

 tm-bid ; on the 28th they were found well filled with 

 Bacteria, which on the 30th had increased to astonishing 

 swarms. On the 15th of October the tubes were again 

 examined, and found charged with undiminished life. 

 They remained thus 'putrid ' until the 14th of Novem- 

 ber. 



During the whole of this time the infusion in con- 

 tact with the moteless air of the chamber remained as 

 clear as distilled water, and entirely free from life. 



On the 14th of November I infected one of the clear 

 tubes by introducing into it through the pipette a few 

 drops of mutton-infusion which had been prepared and 

 exposed upon the 12th of November, and which two 

 days had sufficed to render turbid. On the 15th the 

 inoculated infusion showed signs of turbidity, and on 

 the 16th putrefaction had actively set in, the liquid 

 being thickly muddy and full of life. 



With a moteless chamber and three tubes, experi- 

 ments were subsequently made on a second infusion of 

 mutton. In this case, however, the infusion was boiled, 

 its albumen was precipitated, and removed by filtration 

 prior to its introduction into the chamber. The pellucid 

 liquid was introduced on the 1st of October, boiled for 



