posii 



Dr. J. Wyman — Experiments on Infusoria. 81 



allowed to cool very slowly in order that the entering air may 

 be as long as possible in passing through the iron tubes, and thus 

 the destruction of its organic matters insured. When cold the 

 flasks are sealed at I, figs. 1 and 2, with the blowpipe. 



In experiments xxix and xxx, a glass tube filled with asbestos 

 and platinum sponge was used instead of the iron tube filled 

 with wires. 



The time during which the infusions were boiled varied as will 

 be seen by the records, from fifteen minutes to two hours, and the 

 amount of infusion used was from one-twentieth to one-thirtieth 

 of the whole capacity of the flask, the object being to have the 

 materials exposed to as large a quantity of air as possible. 



In the account which follows, especial mention is made, in 

 most instances, of the time of the formation of the ''film." This 

 is always the first indication which can be had, without opning 

 the flasks, that minute organisms are developed; it is in fact 

 made up entirely of them, as has been proved by repeated ex- 

 aminations with the microscope. It may first be detected in 

 ^mall patches, but soon covers the entire surface, and if the 

 flask is gently moved so as to cause the infusion to change its 

 ion, the film adheres to the glass and is left by the liquid. 

 few of the experiments no such film was formed. 



After the flasks were prepared thev were suspended from the 

 ^alls of a sitting room near the ceiling, where they were ex- 

 posed to a temperature of between 70° and 80° F. throughout 

 the day and nearly the same during the night. 



fxp. L* (l.)5 j^eb 3d, 1862. A few grains each of sugar, 

 gelatine and fine cut hay were introduced into a flask of 500 cub. 

 cent, capacity, 20 cub. cent, of water were added and the whole 

 horoughly boiled. A film formed on the surface of the fluid on 

 oe 8th day, the flask was opened on the 9th and found to con- 

 ^^'n large numbers of Bacteriums. 



^^P- n. (1.) Feb. 3d. This was prepared in the same way 



— -1^ excepting that pepper was added to the solu- 



opened on the 29th day and Bacteriums 



--'una in great numbers. 



I"- (1.) Feb. 4th. A few grains of cheese, sugar and 



- were dissolved in 17 c. c. of water, filtered and boiled in 



-'of 500 c. c. capacity. A film formed on the 19th day, 



r ;ni^ was opened on the 36th and found to contain Bacte- 



jj "^^P- IV- (1.) Feb. 4th. Twelve cubic centimetres of a solu- 

 ^ike the preceding, with the addition of a small quantity of 



itated"bJu?w '*'^^" experiments the time which the contents were boiled is not 

 «f tl j\j,^.^''^^'*^n ^"a'ckSrfXw?^^^^^ number"of"the experiment indicates which 



5 preceding, 

 ,The flask 



