and its relation to Latent Heat. '9 



a vessel of hot water and taking the reading at the instant of 



withdrawal. i r i i 



By a similar method observations were made on alcohol and 



on turpentine. Between 30° C. and 79° the column of alcohol 



descended ~ ; the sample employed had 85 per cent.pure spirit. 



Between 33° C. and 133° the column of turpentine descended 



— ; between 33° and 1651° it descended -^. The sample was 



77' ' *' 



prepared by a chemist, and believed to be pure camphene. 



§ 11. M. Simon (de Metz) in his 'Recherches sur la Capd- 

 larite/ has observations of the influence of temperature on the 

 capillarity of water in tubes of from /^th to j\^^i\^ of an inch 

 diameter : the details of the mode of observation are not stated, 

 but the mean result given is a descent of one-fourth from 0° to 

 100° C. 



The following is quoted from his paper in the Annales de 

 Chimie, vol. xxxii. p. 17 : — 



"Ce rapport 4 : 3 ou 1-33 que donne I'experience conduit il 

 penser que la densite de I'eau est la cause qui produit cctte dif- 

 ference d'asceusion. En eifet, un volume d'eau augmentant de 

 0-0166 pour 100 degres de temperature, il en resulte qu'une 

 colonue d'eau etant 1 tl degre il sera 1-36 k 100 degres : rapport 

 tres voisin du rapport moyen des experiences ci-dessus. L'as- 

 ceusion est done en raison direct de la densite." This conclu- 

 sion is so manifestly discordant with the premises, that it requires 

 to be noted. In the Annales de Chimie for February and March 

 last (vol. xlix.), there is a paper by M. C. Wolf on the influence 

 of temperature on capillarity in tubes of round bore. At p. 359 

 there is a table of observations taken throughout one year at 

 atmospheric temperatures from 0° C. to 35°--l., with a tube of 

 -i-th of an inch diameter, in which every desirable precaution 

 seems to have been taken to ensure accuracy. From 0°-35 to 



6'31 

 25°-45 the descent was observed tqTTTT^' ^""^ ^* ^^ stated that this 



agrees with the previous observations of M. Briinner (Poggen- 

 dorff's Annalen, 1817). If this rate is continued up to the boil- 

 ing-point, the descent from 0° to 100° C. would be ^7^, the 

 height at 0° and from 26^° to 93i° about j^. In another set 



of observations with a smaller tube, the effect of temperature 

 was found to be less by about -r'^jth. It is probaljle that the 

 abnormal feature in the cai)illarity of water in fine tubes affects 

 these results in a greater or less degree. As tlie true measure 

 of the capillarity of hydrous liquids cau only be obtained from 



