INVISIBLE EMISSION OF STEAM. 47 



' Futt concerning the invifible Emifjion of Steam into the Air* 

 W. N. 



DOON after Mr. Giddy had mentioned to me the very re- Steam wasvi- 

 markable and curious facts of which an account is given at acurrent; 

 page I of the prefent Number, I was engaged in the experi- 

 ments on the fimmering of water related at p. 216 of Vol. X. 

 I then made an experiment which may perhaps in a (mall degree 

 elucidate thofe phenomena. A fmall glafs tube was ftuck 

 through a cork, and this was then preHTed into the neck of the 

 retort in which water was boiling over the lamp. The fleam was 

 emitted through this fmaller aperture in a vifible jet of upwards 

 of a foot in length. But when a candle was held with its It became In- 

 flame immediately beneath the end of the tube, the jet became V1 ^ ^" ^ 

 perfectly invifible. To determine whether the water might flame of a 

 be decompofed, or the (ream (imply expanded fo far as to be candle » 

 abforbed by the air, or if condenfed to form a vapour too thin 

 lo be perceived, I fufTered the hot invifible current which had 

 patted through the candle, to pafs through a larger glafs tube. In butthefl-eara 

 this cafe vifible fleam iffiied plentifully from the farther end : w j£ d n . ot *<*"■• 

 Hence, I am difpofed to judge that the large tube having kept 

 the very hot fleam together and cooled it fo as to render it 

 vifible again, there was little if any decomposition of the 

 water. But at the fame time, when we confider the d i fa p- Perhaps fome 

 pearance of the denfe fmoke in Mr. Giddy's experiment, there £ art m »y have 

 feems to be great reafon to think that the charcoal was oxi- 

 genated and gazifled. If fo, the produces muft have been ex- 

 panded and invifible fteam, hidrogen and carbonic acid. By 

 collecting the products in an experiment of this kind, thefe 

 conjectures will either be verified or refuted. If the former, 

 we (hall have the decompofition of water and oxigenation of 

 carbon at a lower temperature than has hitherto been fhewn or 

 expected. 



Experiments 



