314 Heinrich Rose. 
Finally, after the communication by Wurz of his theoretical 
views, according to which the lower acids are to be regarded as 
phosphoric acid in which one or more atoms of oxygen are re- 
placed by hydrogen, Rose wrote, in 1843 and 1846 a careful and 
thorough examination of the arguments in favor of the several 
theories of the constitution of these acids. 
. . . ? ° . . . bd 
bodies, principally volatile metallic chlorids, and give with them 
recisely t 
by Paul Thénard, and condensible at a temperature of —10°C. 
the fact is in direct opposition to an observation of Rose, whieh 
seems to have been overlooked. ‘I made,” says ome 
experiments to see if, by exposure to cold, phosphuretted by- 
wou property of spontaneous inflammability 
= in contact with air. During the severe weather in January, 1823, 
