INVESTIGATION AS TO ORIGIN OF CATTLE DISEASES. 



187 



the sugar solution, witliont at the same time any yeast cells, which it 

 might accideutally contain, also passing into the solution and so vitiat- 

 ing the result. To accomplish this end we availed ourselves of the dif- 

 ferent behavior of yeast cells on the one hand and the various crypto- 

 gamic organisms of putrid fluids on the other, in respect to their ability 

 to pass through certain tissues. jS'ow, bacteria, vibrios, and molecules, 

 either single or in chains, {Monas, 3Iicrozymas^ Micrococcm, Leptothrix, 

 Zoofjiea and Sohizomycetes, of various" authors,) Avill readily pass 

 through thoroughly moistened filtering paper; while, as originally shown 

 by Mitzscherlich, (Pogg. AnnaL, 1855, p. 224,) and again proven by the 

 following experiments, yeast cells will not. Furthermore, none of the 

 above-mention(^d bodies will pass through vegetable parchment, although 

 fluids will. If, then, upon adding a putrefying fluid to a saccharine 

 solution, through the intervention of filtering paper, we produce yeast 

 and fermentation in that solution, while upon making the addition 

 through vegetable parchment we produce none, the method of the 

 experiment leaves no doubt that the yeast must have been developed 

 from cryptogamic germs other than yeast contained in the putrid mat- 

 ter. To carry out this plan of experiment, the following apparatus was 

 used : 



In a four or six-ounce glass beaker (not lipped) was ])laced a tube, 

 made by cutting oft" the bottom of a common test tube, 

 three-fourths inch in diameter and as high as the beaker. 

 This tube was open at the toji, but closed at the bottoUi 

 by two layers of tine, strong filtering ijaper tied tightly 

 over the flaring end with waxed string, and rested on a 

 fragment of glass rod placed in the beaker ; all these 

 articles having been carefully washed, were put together 

 as described, and about two ounces of hot strong alco- 

 hol were poured into both the tube and beaker. A 

 piece of thin sheet rubber was next tied over the top, 

 hermetically closing both beaker and tube, and the 

 whole apparatus, having been thoroughly shaken, so that the hot liquid 

 should come fully in contact with every part, was then set aside to cool 

 until wanted. 



The solution to be experimented on, which had been boiled, filtered, 

 and then reboiled in a flask fitted up as an isolation ai)paratus, was in 

 the mean time cooling in that vessel. When this had cooled to about 

 85°, the alcoliol was removed froai the apparatus and the tube Avas 

 rinsed with a little freshly distilled water. Tiien from one to two ounces 

 of the solution to be experimented on was i)laced in tlie beaker, while a 

 little of the putrefying or fermenting fluid was put in the iniun- tube. 

 Tlie sheet-rubber was finally stretched tightly over all and tied as before, 

 and tlie api)!natus was then kei)t at a^ temperature of 75° Fahrenheit 

 to 85° Fahrenheit in ditfused day light, (Figure -i.) 



FIG. 17 



