936 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



Sensitive Flames. 

 The jumping of a naked fish-tail gas flame, iu response to musi- 

 cal sounds, was fiist accidentally observed by Prof. Lecompte, of 

 South Carolina, at a musical part3\ At a lecture on the subject, 

 lately delivered at the Royal Institution at Great Britain, Prof. 

 Tyndall exhibited some extraordinary experiments. He showed 

 a flame t"VTenty inches long, which was knocked down to eight by 

 a ver}' slight tap on a distant anvil. At a distance of twenty yards 

 the dropping a sixpence from the height of a couple of inches into 

 his hand containing a few coins brought the flames down. It was 

 sensibly influenced by the creaking of boots in walking across the 

 floor. On speaking to the flame it jumped at intervals, apparently 

 picking certain sounds from the utterance, to which it could 

 respond, while it was unaffected by others. 



A New Psychrometer. 

 M. Bequerel has found a new use for thermo-electric bars ; his 

 modification being intended to take the place of a hygrometer, 

 composed of a wet and a dry bulb thermometer. His thermo- 

 electric circuit consists of an iron and a copper wire cf a diameter 

 dependent upon their length ; the longer they are the greater the 

 diameter. Within this circuit is a galvanometer intended to show 

 when the temperature is the same at both points where the metals 

 have been soldered together. One of these points is placed in a 

 medium, the temperature of which is lowered until the needle 

 indicates zero. The second point having attained the same tem- 

 perature is placed in the medium contained in the aqueous vapor, 

 the elastic force of which is to be determined. With the instru- 

 ment he claims to have determined the difference between the 

 elastic force of aqueous vapor just above the surface of a river, and 

 at a point three meters higher. 



Water-Glass on Wooden I]loors. 

 A Hamburg paper strongly recommends soluble glass (silicate 

 of soda) as a coating for floors. Before applying the coating the 

 floor should be well cleansed and the spaces between the boards 

 be filled Avith a mixture of silicate and chalk, or gypsum made 

 into a thick dough, which quickly sets into a hard mass. The 

 floor may then be brushed over with a solution of silicate. If 

 colors are employed, most vegetable pigments must be avoided, 

 because of the alkali in the solution. The mineral colors used 



