PUTEEFACTION AND INFECTION. 71 



troduced into its case on the 3rd of January. The warm 

 air of the room had, however, so acted on the wood of 

 the chamber, which had been employed in former ex- 

 periments, that the water of condensation trickled from 

 a chink in the bottom. The other chambers were 

 mended as far as possible, and into them tlie infusions 

 were introduced on the 4th of January. Each chamber, 

 as before, was provided with three exposed tubes for 

 comparison with three protected tubes within. On the 

 morning of the 6th the exposed turbot-infusion was 

 clear in all the tubes ; a few hours subsequently two out 

 of the three became cloudy ; while on the 7th Bacteria 

 had taken, possession of all of them. All the impro- 

 tected tubes of codfish were cloudy on the 6th, more 

 cloudy on the 7th, and covered with a soapy layer upon 

 the 8th. The three exposed herring-tubes were also 

 cloudy on the 6th, the cloudiness advancing afterwards 

 to thicker turbidity. The mullet gave way in the same 

 manner. For more than three months the 'protected 

 tubes, including even the imperfect chamber which 

 protected the TnuUet-infusion, have remained as clear 

 as they were upon the day of their introduction. 



To these fish-infusions may be added others of eel 

 and oyster. Two tubes of each, protected by lamp- 

 glasses, were charged on the 27th of December. They 

 remain unchanged. Two other pairs of tubes, prepared 

 in the same way and exposed to the laboratory air, are 

 turbid and covered with Penicillium. 



§ 13. Infusions of Fowl and Kidney. 



Three tubes . of the fowl-infusion were introduced 

 into a case, and boiled there for five minutes, on the 

 4th of January. Three similar tubes were at the same 

 time exposed to the air. On the 6th all the outer 



