168 DEPARTMENT OP AGRICULTURE. 



Experiment 1. On the 24th of March, 1869, solution A was placed in five beakers, 

 the tubes of which were closed with paper. In the tube of No. 1 was put a teaspoonful 

 of fresh yeast; in those of Nos. 2 and 3 some putrefying fluid from lung of a pleuropncu- 

 monic cow; in No. 4 was placed a fluid containing large and lively bacteria taken from a 

 can of preserved roast meat which had spoiled; to No. 5 nothing was added. Two ounces 

 of the solution were also retained in the flask which had remained uncorked for fifteen 

 minutes. 



In twenty-four hours the rubber cover of No. 1 was distended, presenting a well- 

 marked convexity. Bubbles of gas were rising in the tube, but none in the beaker. The 

 covers of Nos. 2, 3, and 4 were slightly distended, and a few bubbles appeared on the out 

 side of the tubes. No. 5 was unchanged. 



In forty-eight hours the covers of the first four beakers were strongly distended, show 

 ing that the closure was perfect, (an important point.) 



In No. 1 the bubbles were still confined to the inside of the tube, while in Nos. 2, 3, 

 and 4 they were chiefly on the outside of the tubes. No. 2 was now opened. The fluid 

 in the beaker was turbid, filled with molecules, chains of granules, and bacteria. It also 

 contained well-marked yeast cells, separate, and just beginning to bud. 



The next day, March 27, beakers 1, 3, and 4 were opened. In No. 1 the yeast was 

 confined to the tube, in which it was in full growth. Not one yeast cell could be found 

 in the outer fluid. 



In Nos. 3 and 4 there was abundant growth of yeast in the beakers; greatest in No. 

 4. In No. 5 there was no change, nor has any occurred at this date. 



At the same time that the beakers were arranged a series of growing slides was pre 

 pared and charged with the same fluids. The changes in these corresponded precisely 

 with those in the beakers, except that they were more slow. 



Experiment 2.- Two beakers were arranged with solution A. The tube of No. 1 

 w r as closed with vegetable parchment, that of No. 2 with filtering paper. Putrefying 

 fluid from the lung of a^leuropneumonic cow was placed in the tubes, care being taken in 

 No. 1 that this fluid should stand at the same height as the solution of sugar in the 

 beaker. 



In twenty-four hours decided osmose from the tube to the beaker had occurred 

 in No. 1, and the rubber cover was concave. In forty-eight hours the cover was still 

 concave, and the fluid in the tube was three-fourths of an inch lower than in the 

 beaker. In beaker No. 2 the cover was distended, and yeast was evidently in active 

 development. 



Four days later the beakers were opened. The cover of No. 1 was now very slightly 

 convex ; yeast cells were found in the tube, but none in the beaker, although the latter 

 contained molecules or micrococcus. In No. 2 the cover was now concave, owing to 

 fructification of penicillium within the tube. Yeast cells were found abundant in the 

 beaker. 



Experiment 3. Eight beakers were arranged with solution B, the tubes being adjusted 

 as follows: 



Nos. 1 and 2, closed with filtering paper; contents, putrefying roast beef. Nos. 3 

 and 4 closed with filtering paper; contents, blood of pleuropneumonic cow. No. 5, closed 



