> 



188 DEPARTMENT OF AGRICULTURE. 



The solutions used were of caue or grape sugar, mixed witli extract of 

 beef, or with tartrate of amiuonia and ashes of yeast. 

 The two foHowing forniuhe gave the best results : 



A. 



Cane sugar 10 parts. 



Tourtelot's extract of beef 10 parts. 



Water 100 parts. 



B. 



Caue sugar 10 parts. 



Tartrate of auiinonia 5 parts. 



Ashes of yeast o parts. 



Water 80 parts. 



Experiment 1. — On the 21:th of March, 18G9, solution A was placed 

 in five beakers, the tubes of which were closed with paper. In the tube 

 of 2«ro. 1 was put a teaspoonful of fresh yeast ; in those of Jfos. 2 and 3 

 some putrefying fluid from lung of pleuro-pneumonic cow ; in Xo. 4 was 

 placed a fluid coutaining large and lively bacteria taken fi'om a can of 

 preserved roast meat which had spoiled ; to No. 5 nothing was added. 

 Two ounces of the solution were also retained iu the flask which had 

 remained uncorked for fifteen minutes. 



In twenty-four hours the rubber cover of No. 1 was disteiuled, pre- 

 senting a well-marked convexity. Bubbles of gas were rising iu the 

 tube, but none iu the beaker. The covers of Nos. 2, 3, and 4 were 

 slightly distended, aud a few bubbles appeared on the outside of the 

 tubes. No. 5 was unchanged. 



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

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



In No. 1 the bubbles were still confined to the inside of the tube, 

 while iu Nos. 2, 3, aud 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, aud bacteria. It also contained well- 

 marked yeast cells, separate, and just beginning to bud. 



The next day, ]\Iarch 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 abuiubmt 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 prepared and charged with the same fluids. The changes iu 

 these corresiK)n(h'd precisely with those iu the beakers, except that they 

 were more slow. 



Experiment 2. — Two beakers were arranged with solution A. The 

 tube of No. 1 was closed with vegetable parchment, that of No. 2 with 



