(416) 
The result was very satisfactory as the readings of the boiling 
points only showed a difference of at most 0.003° when the tempe- 
rature was lowered to the extent of = 0.5°. Finally it was ascer- 
tained what influence was exercised on the boiling point by the 
method of heating. An experiment showed that the turning of the 
flames either up or down, did not affect the boiling point as long as, 
the liquid was kept actively boiling. 
Way of Experimenting. 
The experiment may now be made as follows: — First of all 
distilled water is introduced into both boiling vessels, and also 
grains of enamel and silver tetrahaedra, whilst the quantity of water, 
intended for the vessel in which salt is afterwards to be dissolved, 
is being weighed. The four burners are next lit, water being allowed to 
flow through the large condensers A and A’. When the water boils 
both in the copper waterbath and the silver cylinders, the flames 
under the waterbath are turned low and those under the silver ves- 
sels are regulated. By means of the rubber tube m. the silver cylinders are 
connected with the manostat and the latter is set in action. To 
know the pressure which exists in the apparatus during this first 
experiment, the barometer and the watermanometer of the manostat 
are read off. 
After a quarter of an hour, both the thermometers are read off 
by means of a magnifying glass and the correction with the mano- 
stat is interrupted. The burner underneath the vessel intended for 
the salt is removed and water is passed through the small condenser. 
The stopper of the small condenser may then be removed without 
fear of any loss of watervapour. A weighed quantity of salt is now 
introduced and the stopper reinserted. The burner is now replaced 
underneath the boiling vessel, while the water is allowed to pass 
for some time through the small condenser to rinse down small 
particles of solid matter adhering to the inside of the condenser by 
means of the condensed steam. After a while, the boiling vessels are 
again connected with the manostat and the latter is so arranged that 
the boiling point of the salt solution is the same as that of the water ; 
the thermometers are read off at intervals. The fall observed in the 
thermometer which is placed in the boiling water, corresponds with 
the decrease in vapour tension of the solution at the temperature 
of the salt solutions, which is the same for every concentration. 
The results of my investigation will be communicated after the close 
of another investigation, which I have started with Mr. Po. KOHNSTAMM 
