( 236 ) 



March '03, PI. II, figs. 1 and 2) contains the gaseous mixture Avliich 

 has been prepared in it bv means of the apparatus connected at 

 Vf, and /'„ (comp. Comm. n". 84). Through tlie cock r^,, the steel 

 capiUarv ƒ// and the steel tliree-wav stopcock k (see Comm. N". 84, 

 PI. I, fig. 2) it is led to tiie pressure tube // witli calibrated stem 

 (see Comm. N^ 69, April '01, PI. II) phiced in tiie pressure cylinder '51/ 

 (Comm. N". 84, PI. 1) in order to be compressed bv means of 

 mercury from tlie i)ressure reservoir f\' (comp. Comm. N". 84). 

 Thence through the three-way stopstock /• and the steel capillary 

 ^/i" it can be brought under pressure into one of the two apparatus 

 X> or '^. For tiie present, according as we wanted to determine either the 

 begin or end condensation pressure y>,u7' or ph-r^ we have connected 

 either the capillary of 2), t)^., or tliat of '^ \Y:! ^^ the capillary g^" 

 by means of sealing wax. 



Different from Comm. N". 84 Pi. I fig. 1 tlie mercury of the 

 pressure cylinder (see our plate tig. J) is also connected by means 

 of n with that of a manometer to determine the pressure in X> 

 or %\ 



By means of the three-way stopcock /• the apparatus 5^ or ^^^ may 

 also be connected directly with the voluniciionieter and then the 

 pressure is measured by means of M. 



A detailed representation of the apparatus D and 'P is given in 

 figs. 2 and 3 of PI. 1 and a doscri|>ti(»ii in §§ 4 and 5. In both cases 

 the glass tube to which the mixture which is to be investigated is 

 conducted by means of the capillary y/', /) in 'X' ^^Jxl 'f hi D, is 

 immersed in a cryostat where the desired temperature is kept in the 

 same way as descrii)ed in Comm. N". S3 (Feb. and March '03). 



The regulation is Itrought about for ']> through the exhaust-tube 

 7'i2 and for 2) tiirough the tubes /', and ///.,. In our measurements 

 we brought licpiid methylchloride into the cryostat and the tempe- 

 rature was regulated according to the indications of an alcohol ther- 

 mometer. 



By means of the cock y, the volumenometer 7:^ is connected not only 

 with the gasreser\oirs but also with the mercury airpnmp so that also 

 the pressure-tube and the test-tube in r* and 'P can be exhausted. 

 We shall not expatiate on the process of tilling the api)aratus with 

 a definite quantity of the desired mixture and of measuring any 

 quantity of gas which we allow to escape from them. For the 

 rest we refer to Comm. N". 84 for the volumenometer and the 

 mixing apparatus, to Comms. N". 69 and N". 84 for the pressure 

 cylinder and its appurtenances, to §§4 and 5 and Comm. N". 83 for 

 the cryostats. 



