Mat, 1S42.] 169 



Dr. Chaloner made inquiry with regard to some Infusoria 

 said to have been discovered in the green sediment of pools ; 

 and which are stated to possess the peculiar property of evolv- 

 ing oxygen gas under the influence of the sun's rays. 



When examined by the microscope, they rose to the sur- 

 face, emitted a bubble of gas and then subsided. This gas, 

 collected in an inverted jar, was found on analysis to yield 

 about 80 per cent, of oxygen. 



Dr. B. H. Coates then made some remarks on the progress 

 of discovery in relation to this class of animals ; and called the 

 attention of the members to the late work of Mr. Pritchard, 

 and communicated some of the information which he had 

 derived from this author. 



Dr. Bridges remarked that, in relation to the first mentioned 

 discovery, in the absence of more definite information, the 

 facts which had been communicated would lead us to suppose 

 that the subjects of observation were of a vegetable nature ; 

 since it is well known that vegetables under the influence of 

 the sun's rays, evolve oxygen by the decomposition of car- 

 bonic acid, which is always present in the atmosphere and in 

 water. He also alluded to the difficulty of discrimination 

 between animal and vegetable bodies, especially in micros- 

 copic objects, and made reference to a paper on the Sponge, 

 in one of the late numbers of the Transactions of the Linnean 

 Society, to illustrate the great accuracy of observation re- 

 quired in these cases. 



BUSINESS BY SPECIAL RESOLUTION. 



The following resolution was adopted : 



Resolved, That the Sth Vol. of the Journal of the Academy 

 be presented to M. de Longchamps. 



