419 
. Evidently tlien, the temperature coefticients of Kohlrausch can 
not be relied on to obtain accurate values at 0°C. 
Wood 1 2 ) has given the following values for at U°: for KCl = 
77.8, for NaCl = 85.0, for dichloracetic acid = 227.0, for trichlor- 
acetic acid = 224.7. Thus from the values obtained by rne it is 
seen that his values for KCl and NaCl are a little too low, whilst 
bis values for the acids are very inuch too low, since the most 
probable value of H° is 223.9. 
Johnston’s a ) rough estimation of the value of H° at 0° = 240 is 
also far from being correct. 
Noyes and Stewart 3 ) have deduced values for H° in an indirect 
way which can hardly be relied on. Whilst from data for HC1 they 
obtained the velocity for H° at 0°=r 224, they, at the same time 
obtained, by considering H 2 S0 4 in the same way the value 235 at 0°. 
Noyes and Coolidge 4 j give 81.4 as the value of p^ for KCl at 
0°; but it is a little too low. 
Jones and West 5 ) have given p^-, at 0° for NH 4 C1 = 74.84; 
evidently it is too low. 
Jones and Caldwell 6 ) give the value for ammonium nitrate 
= 78.0, which is a value a little too low. 
Kahlenberg 7 ) obtains for strontium nitrate the value 66.1. Evidently 
it is too low, since the correct value would be about 31.7 — f- 41.3 == 
73 (loc. cit). 
Hill and Sircar 8 ) take a very high value for H° at 0°. They 
write: For Pqq in the case of hy drogen fluoride, we have taken 
the number 364 at 18° and 325 at 0°. The first number is derived 
from the ionic conductivities at 18° which are 318 for the hydrogen 
ion and 46.6 for the fluorine ion. The second number is derived 
from the following data: 
“Ostwald gives 325 as the ionic conductivity of the hydrogen 
ion at 25° ; at 18° the value is 318 (Kohlrausch and v. Steinwehr, 
Sitz.-ber. Berlin. Akad. 1902), being a fall of one unit per degree. 
Hence at 0° the value would be approximately 300. Correcting 
the ionic conductivity of fluorine for temperature, the temperature 
coëfficiënt being 0.0238, we get the value at 0° = 26.6. The sum 
0 Loc. cit. 
2 ) J. Amer. Chem. Soc. 31, 1015 (1909). 
s ) J. Amer. Chem. Soc. 32, (1910), 1140—1141. 
4 ) Garnegie Institution Publications 63, 47 (1907). 
s ) Amer. Chem. Jour. 34, 557 (1905). 
6 ) Amer. Chem. Jour. 25, 349 (1901). 
7) Jour. Phys. Chem. 5, 339 (1901). 
8) Proc. Roy. Soc. Vol. 83 A, p. 130. 
