110 WYMAN, ON THE FORMATION OF INFUSORIA. 
is the atmosphere. In support of this opinion he asserts, that 
when a fluid containing organic matter in solution is put into 
a flask and “ boiled two or three minutes,” and supplied only 
with air which has been filtered by passing through a tube 
heated to redness, and the flask is then hermetically sealed, 
no fermentation takes place, no organisms are formed, and 
that the contents remain indefinitely without change. But if 
the same solution is exposed to the air in its ordinary condi- 
tion it becomes filled with various living forms. Out of a 
large number of experiments prepared in the manner above 
described, he has not known one to give a different result 
from that mentioned.* He further states that if the neck of 
the flask is drawn out into a very slender curved tube of 
several inches in length, the contents boiled, and then allowed 
to cool without the end of the tube being closed, so that the 
air enters at the ordinary temperature, and has free access to 
the interior of the flask, even then no fermentation takes 
place, and no organisms appear. His explanation of this is, 
that the air which enters first, meets with the hot steam, and 
the spores or organisms contained in it are killed, while those 
which enter the tube later move more slowly, and are depo- 
sited on the moist walls of it, without entermg the body of 
the flask.+ 
In most of the experiments given below, the results have 
been quite different, and living organisms have made their 
appearance in some instances where even greater precautions 
were taken than those mentioned by Pasteur. In order that 
the reader may understand what precautions were taken, we 
shall first describe the manner in which the experiments were 
performed. 
(1.) In some instances (as in Experiments | to 5, 7 to 11, 
13 to 15, 29 and 30 inclusive) they were prepared as in fig. 1. 
The materials of the infusion were put into a flask, and a 
cork a, through which was passed a glass tube, drawn to a 
neck at 6, was pushed deeply into the mouth of it. The space 
* “Paffirme avec la plus parfaite vérité que jamais il ne m’est arrivée 
d’avoir une seule expérience disposée comme Je viens de le dire, qui m’ait 
donné un seul resultat douteux.”—Aznales des Sciences Naturelles, t. xvi, 
iv™ serie, 1861, p. 33. 
+ “Il semble que l’air ordinaire rentrant avec force dans les premiers 
moments doit arriver tout brut dans le ballon. Cela est vrais, mais il 
rencontre un liquide encore voisin de latemperature d’ebullition. La rentrée 
de |’air se fait en suite avec plus de lenteur et, lorsque le liquide est assez re- 
froidé pour ne plus pouvoir enlever aux germes leur vitalité, la rentrée de 
Pair est assez ralenti pour qwil abandonne dans les courbures humides du col 
toutes les poussieres capables d’agir sur les infusions, et d’y determiner des 
productions organisées.”—Ann. des Sc. Nat., 1861, t. xvi, p. 60. 
