3 



NEW METHOD FOR DETERMINING COMPRESSIBILITY 



Moreover Perkin 1 found 1.5008 at i5/i5 and 1.4849 at 25/25. 

 These values of Perkin's reduce to 1.4993,1 5 /4, and 1.4801, 25/4. 

 If the values of these three observers be plotted the interpolated value 

 for the density at 20/4, is found to be 1.490. 



In order to obtain the other compound of chlorine in a pure state, 

 tetrachlormethane of commerce was twice distilled, and the fraction 

 coming over between 76. 6 and 76. 8 C. (cor.) was used. This sub- 

 stance has a higher specific gravity than chloroform. Thorpe 2 found 

 (o/4) 1. 63 1 95 and a volume increase of 2.45 per cent, at 20 . 

 These values give 1.593 ( 2 /4)' 



The method of determining the compressibility of these substances 

 was precisely similar to that used in the case of bromine. The glass 

 jacket II, containing the maximum amount of 437 grams of mercury, 

 was used in each of the four series given below. The weight of the 

 chloroform was 5.354 grams, hence its volume was 3.590 milliliters, 

 while the corresponding data in the case of the carbon tetrachloride 

 were 6.970 grams and 4.403 milliliters. The weights of the two thin 

 bulbs were respectively 0.55 and 1.06 grams. Series 13 was obtained 

 by taking out mercury instead of adding it. Its perfect agreement 

 with series 12 shows that the apparatus was in excellent order. 



Data for Chloroform and Carbon Tetrachloride. 



Carbon tetrachloride. 



This table contains all the data, in addition to the previously re- 

 corded figures, necessary for computing the compressibilities of the 



>Journ. Prakt. Chem. (2), 32, 573 (1885). 

 a Journ. Chem. Soc, 37, 198 (1850). 



