The Origin of Infusoria. 321 



As we stated in a former paper, the simplicity of the appa- 

 ratus employed by M. Pasteur gives great value to his experi- 

 ments, for it must be extremely difficult to shut out all sources 

 of error, when a series of vessels with numerous joints are 

 employed, but some of his opponents deserve equal credit for the 

 method they have adopted. Practically the question to be 

 first decided is, whether any vital organisms can appear in 

 infusions in which existing germs have been destroyed, and to 

 which the access of fresh germs is rigorously prevented. It has 

 been assumed that boiling an infusion destroys any life or germ 

 of life that it contains, and that when air is made to traverse a 

 red-hot tube a similar result takes place. Now it cannot jbe 

 said that, in adopting these methods, M. Pasteur has "proved" 

 the necessary non-appearance of infusorial organisms, as Dr. 

 Sharpey asserts, because opposite results have been obtained by 

 other able experimenters who have made analogous trials. In 

 France Messrs. Pouchet, Joly, and Musset, and in America 

 Professor Wyman, adduce experiments that flatly contradict 

 those of M. Pasteur. We gave some account of Mr. Wyrnan's 

 experiments in number ix, p. 229, and they will be found in 

 detail in Silliman's Journal, or in the Chemical News of 

 August 30th. Several of these trials were made as described 

 in the following extract : — " Two flasks each of 550 c. c. capa- 

 city, and each containing about 20 c. c. of beef juice and urine, 

 were hermetically sealed at the temperature of the room, 

 wrapped in cloth, and exposed for two hours in boiling water. 

 The film, formed on the fourth day. One of them was opened 

 on the fifth, and the other on the eleventh, aud both found to 

 contain Bacteriurns." In experiment 35, pieces of mutton in a 

 hermetically sealed flask were boiled for ten minutes in a Papin's 

 digester, under the pressure of five atmospheres. " No film 

 was formed. The flask was opened on the forty-first day. 

 Monads and vibrios were found, some of the latter moving 

 across the field. No putrefaction, the solution had an alkaline 

 taste." In four instances out of thirty-three no organisms 

 appeared, but the balance of the results was discordant with 

 those of M. Pasteur, Professor Asa Gray being present at the 

 opening of some of the flasks. In experiment 12, the juice of 

 an ounce of beef, to which was added 10 c.c. of urine and 

 40 c. c. of water, was boiled twenty minutes in a bolt-head and 

 hermetically sealed. A film formed on the fourth, and the 

 flask was opened on the eleventh day, when there was a distinct 

 rush of air outwards. Large numbers of Bacteriums were 

 found, also small spherical bodies with ciliary motions and 

 oval bodies like kolpods, containing what appeared to be Bac- 

 teriums. One of these kolpod-like bodies moved with cilia. 



After these experiments, it is obvious that there is some- 



