612 PEOFESSOE BUNSEN ANT) DE. H. E. EOSCOE’S PHOTO-CHEI^nCAL EESEAECHES. 
vessel, and from the diminution of the action from lo to I, the values of - were cal- 
culated as in the previous instance. Chlorine was again expelled from the cylinder into 
the reversed retort, the cylinder again placed between the flame and the instrument, the 
values of lo and I again determined, and this repeated until the whole of the chlorine 
had been displaced. The agreement of the sum of all the separate determinations of 
chlorine with the total quantity introduced, served as a control for the accuracy of the 
analyses. 
The calculation of the volume of chlorine at 0° C. and O' 76 pressure, from the direct 
observations of the volumetric analyses, was made by means of the formula c= 88-012 
a{nt—t^), which we deduced in a former communication. 
Experiment gave — 
Series of Experiments IX. 
(1) Capacity of cylinder filled with chlorine at 16° C. and 0'7453 
pressure 190'24 cub. cent. 
(2) Contained volume of chlorine at 0° C. and O' 76 pressure . . 176 '2 4 cub. cent. 
(3) Height of the cyhnder H 83'8 millims. 
(4) Length of the column of chlorine reduced to 0° C. and O' 76 
pressure 77'63 millims. 
Analyses of the displaced chlorine : 
First portion .... 
Second portion .... 
Third portion .... 
Fourth portion .... 
a=0'001944 
a=0'001944 
a=0'001944 
a=0'001944 
?^= 43'1 
^= 42-5 
j^=42'3 
#=42'2 
^j=16'3 7 
4'4 71=- 4 
ifj=17'0 4 
2'0 71=10 
Hence the volumes of chlorine at 0° C. and O' 76 pressm’e are found to be — 
Original volume of chlorine in cylinder . . . . 176 '2 4 cub. cent. 
Volume of first portion displaced 48'83 cub. cent. 
Volume of second portion displaced 2 8' 34 cub. cent. 
Volume of third portion displaced 26 '04 cub. cent. 
Volume of fomlh portion displaced 71'86 cub. cent. 
175'07 cub. cent. 
Hence it is seen that the sum of the quantities found in each analysis agrees with the 
quantity originally taken, 176 '2 4, as nearly as could be expected, considering the number 
of analyses made. From these numbers the values of h are obtamed, that is, the length 
which the columns of gas would have been, had they been mimised -svith ah' and 
measured at 0° C. and 0'76 pressure. 
1. Height of the total quantity of chlorine 77'6 millims. 
2. Height after displacement of first portion .... 56'2 millims. 
3. Height after displacement of second portion . . . 43'6 millims. 
4. Height after displacement of thhd portion . . . . 32 '2 millims. 
