28G 
MR. J. 13. HANNAY ON THE MICRORHEOMETER. 
Acid. 
Rates. 
Differences. 
hno 3 
131-4 
+ 0T 
HC1 
136-3 
+ 5-0 
MToScq 
141-8 
+ 10-5 
Water 
131-3 
At first thought, we would expect that the acids being salts of' the monatomic metal 
hydrogen, and so exactly comparable with potassium and sodium salts, would show the 
same microrheometrical reactions; but when we consider, in the first place, the very 
weak saturative power of hydrogen (as a base), and also that the salt of hydrogen is 
dissolved in its own oxide, we see that it is probable that the results will not agree 
with those of a strong monatomic base like potassium. The relation of the acids 
require a much fuller investigation, as it has lately been shown that acid which has 
been allowed to stand for some time does not evolve so much heat on saturation with 
an alkali as acid which has been freshly prepared. Hence on further investigation 
the above rates may require alteration. 
Lastly, as to mixtures. A large number of mixtures have been done, and as they 
all give exactly the calculated number, only one example need be quoted here by way 
of illustration. A solution was made up by mixing equal parts of the following normal 
solutions : — 
KNOg, KoS 0 4 , NaNOg, NaCl. 
Each salt, therefore, exerted only one-fourth of its influence, which gives by calcula¬ 
tion a rate of 
-4-9 +12-3 + 6-6 +9-4 
4 + 4 + 4 + 4 “^ 
131-3 = 136-9". 
Average of 10 experiments 
Probable error of mean. 
0-06" 136-85". 
Of course, as each metal and each acid has a value of its own, it does not matter how 
they are distributed, thus affording further conclusive proof that neither solubility, 
crystalline form, nor specific volume have any effect upon the microrheosis of a salt. 
From the above facts we see that the microrheometer, not merely dealing with 
the superficial qualities of chemical matter, but bringing to light the fundamental 
relations of mass and energy, is likely to become the centre of a new branch of the 
science. My next work will consist of an examination of liquid bodies whose thermal 
relations are known, so as to find a fundamental relation between the energy expended 
by elements in forming a certain mass of substance, and the retardation offered by such 
substances in the microrheometer. 
