the Transparent Liquids by Increase of Temperature. 351 



Temperature 



Apparent vo- 



The volumes 





by Centigrade 

 thermometer. 



lumes of liquid 



sulphurous acid 



observed. 



calculated by 

 the formula. 



Differences. 



o 



0- 



1-00000 



1-00000 



•00000 



12-6 



102300 



102242 



- -00068 



26-4 



1-05086 



1-04996 



- -00090 



350 



1-06983 



1-06897 



-•00086 



49-5 



1-10479 



1-10484 



+ -00005 



62-5 



1-14029 



114188 



+ •00159 



72-5 



1-17100 



1 17421 



+ 00321 



82-5 



1-20576 



1-21055 



+ 00479 



910 



1-23932 



1-24519 



+ -00587 



1000 



1-27958 



1-28635 



+ -00677 



108-5 



1-32379 



1-33025 



+ •00646 



115-5 



1-36641 



1-37079 



+ -00438 



1220 



1-41325 



1-41262 



- -00063 



126-8 



1-45380 



1-44650 



- -00730 



M. J. Is. Pierre investigated, in most valuable experiments, 

 the expansions of forty-four transparent liquids, at temperatures 

 below their boiling-points under atmospheric pressure. He con- 

 cluded that they follow very different and complicated laws of 

 expansion. I believe it will be found generally (water being the 

 only known exception) that the transparent liquids follow the 

 same law of hyperbolic expansion, but that the three constants 

 a, b, and c 2 have very different values for different liquids. 



Aldehyde being the most expansible of the liquids which he 

 tried, and, as he concluded, the most expansible of all liquids 

 then known after the liquid carbonic acid, I examined first the 

 degree of its accordance with the hyperbolic law. 



The circumstances of M. Pierre's experiments are a little dif- 

 ferent from those of M. Drion, the liquid being under atmo- 

 spheric pressure at its free upper surface in his instrument in 

 the form of a thermometer ; whilst the experiments of M. Drion 

 were made with a closed instrument of like form, and the liquid 

 was thus subject to the variable pressure due to the elastic force 

 of its vapour only at its surface. The compressibility of liquids, 

 according to Canton's law, is so very small that the correction of the 

 volumes on this account for even high pressures will be very small. 

 The values of the constants a y b, c 2 for aldehyde were deter- 

 mined from M. Pierre's results at the temperatures — 20 o, 69 C, 

 + 12°-07 C, and +21°-32 C, the liquid boiling at 22° C, and 

 its specific gravity being -80551. 

 The values, as follows, 



a = -5688698, 



b = 261-5555, 



c 2 = 112-8826, 

 differ only in a moderate degree from the like values for hydro- 

 chloric ether, but very considerably from those for nitrous acid. 



