Chemistry and Physics, 65 
known, the volume is calculable at the temperature and pressure 
of the experiment, and hence the volume V of the trichloride is 
7 
known. Its weight, W,= in grams. From 
71(c,—6,)—44(e—6)’ 
these data, the density is obtained since w= D. The result with | 
ICl, gave 3:1107, which the author thinks too high.— Ber. Berl. 
Chem. Ges., x, 782, May, : ae 
3. On the Determination of High Melting Points,—CaRNELLEY 
has proposed a new process for fixing the melting points of less 
readily fusible salts, founded on the principle that if three metallic 
salts A, B and ©, which fuse at different temperatures such that 
A fuses before B and B before C, be arranged on a cold block of 
smooth iron and this be placed in a muffle kept at ‘a constant 
high temperature, and if 2 be the number of seconds which elapse 
between the melting of A and B and y, the number of seconds 
between the melting of A and ©, then the ratio ¢ is approximately 
constant for the same three salts whatever may be the temperature of 
the mufile, provided only it is considerably higher than that at which 
C fuses. Thus in sixteen experiments, using the three substances, 
sulphur, silver nitrate and potassium nitrate, the experiments being 
made at widely different temperatures, the ratio in each was 2°67, 
2°68, 2°81, 2°80, 2°72, 2°67, 2°67, 2°67, 2°56, 2°62, 2°58, 2°87, 2°65, 2°88, 
_ 2°71, 2°91; mean 2°72. If the ratios obtained with different salts 
be reduced to the same scale, as by assuming the ratio between sal- 
phur and potassium nitrate and any other third salt to be any 
given number, the value for a given salt is constant, whatever the 
other salts used with it in the experiment. From these ratios, 
time-values are obtained for nine standard salts, S, AgN 2 
0,;, KCIO,, TICI, PbCl,, KI, KCl, and Na,CO,. Thus if in 
This (or the mean of a larger series 26:4) 
: F KNO,. So 32 is the time-value for 
KClO,, 45 for TICI, 59 for PhCly, 115 for KI, 197 for KCl, and 
458 for Na,CO,. From the equation voor, in which ris the ex- 
perimental ratio for any salt, the time-value of that salt may be 
obtained. Thus with 8, AgNO, and KCIO,, if r=2-72, 42°72; 
ence if c=10, y=27-2, the time-value. Or, again, the value 
sid for PbCl,, KCl and Na, CO, is 1°50. Since the time-values 
the two former are 59 and 197, r==138, and y=207; or Na,CO, 
— 207 seconds after PbCl, ; and since PbCl, melts 59 seconds 
F ‘er 8, the time-value of Na, CO, is 266 seconds. By accurately 
etermining the melting points of these nine salts, and collating 
AM, Jour, oretide se Sentzs, Vor. XIV, No. 79.—Juxy, 1877. 
