Chemistry and Physics. 461 



The observer mentions that in Shaft II there was at the 



depth of Oil m. a seam of coal, in which heat was generated 



of the other shafts, although it is obvions that some disturbing 

 cause has rendered the temperatures in shaft IV ahnoriuallv 

 high. Possibly the heat generated in boring the holes for the 

 thermometers 'in this shaft (which was dry) has vitiated the 

 observations, the instruments employed being maximum ther- 

 mometers. Two of the slow non-registering thermometers 

 mentioned in last year's report have been sent to M. Delesse, 

 to be used for verification. 



The slow-action thermometers are constructed on the follow- 

 ing plan: The bulb is cylindrical and very strong, and is sur- 

 rounded by stearine or tallow, which fills up the space between 

 it and a strong -lass shield in which the thermometer is in- 

 closed. The shield is not hermetically sealed (not being intended 

 for protection against pressure), but is stopped at the bottom 

 with a cork, so that the thermometer con be taken out and put 

 in again if desired. Stearine and tallow were selected, after 

 trials of several substances, including paraffin wax. bees" wax, 

 glue, plaster of Paris, pounded glass and cotton wool. The 



rubber. When placed, without these cas s, in water differing 

 10° from the ii >wn ten ! they take 1 rl If a minute 



to alter by one-tenth of a degree. 



In concluding this report, your committee desire to express 

 their regret at the losses vhich the\ 1 v< >u> ned L\ the 

 deaths of Professor Phillip-. Sir Charles Lvell. and Col. Strange, 

 of whose valuable service- thev have been deprived within the 

 last three years. 



SCIENTIFIC INTELLIGENCE. 

 I. Chemistry and Physics. 

 1. On Iodine Trichloride.— Cheimoman^ 1, .< d< * n\> 1. a- in 

 excellent lecture experiment, the pivparati 

 chloride ly rlc- u-tion <>t Iry ehlorh e up • 



■ . 

 nr-(I.,=HCl+IClandlCl+ 

 C1., = T("1 A- rl. M-t ta.-t <>f the two « st- 



whir.- ,!,.,;,. cloud oflivdrouvn i 



)■<■.'. ,■•>■.■■■• . ■■ _ '- '.-:.- •■ ■'■■■■ ' ' ■ " ; " 







fre.pu-utlv Iji Mieut of great splendor. il 



walls of the vessel ire cov.-ivd with i i -k, bright lemon-yello 

 crystals, which are converted into the monochlonde by an exee 



