132 G. H. KNIBBS. 4 
The values given by me are obtained by interpolation: in the — 
original work the temperature-intervals are irregular. 
Phibram and Handl, 1878.—I have not reduced the observa- 
tions of these investigators. The times of efflux are short, about — 
84 to 199 seconds, the temperatures are at irregular intervals from _ 
13-9° to 56°4°.1 : 
Grotrian, 1879.—The lengths of the two tubes used by Grotrian 
were measured by a cathetometer to 005 c.m., at what temper — 
ture is not stated, and their sections were derived from measure 
ments of their capacity.2 The content of the measuring bulb was 
40°3465 grammes at 16°.57 C.: its capacity was evalued by — 
Grotrian for 28° the middle temperature in his efflux experiments. 3 
Assuming however that the other measurements were also 
made at about 16°.57 I have, as is requisite, found the capacity 
for that temperature, the result being 40°390 c.cm. The apparatus 
was wholly submerged in the heating bath. 
Slotte, 1881.—With the one tube Slotte measured the efflux 
four times at each of the temperatures 10, 20, 30 and 40 degrees 
C., these being registered by a corrected (justirtes) thermometer, 
graduated to tenth degrees.2 No information is given in the 
account of his experiments as to the conditions under which he 
dimensions of his apparatus was ascertained. The apparatus and 
method of using it was similar to Sprung’s, hence dimensional 
temperature corrections are not needed. Slotte proposed "7 
formula by which the viscosity might be put in the form* 
—C. 
i B+r 
He used Hagenbach’s correction.5 
eee 
1 Sitzber. Akad. Wien., Bd. 78, Abt. 2, p. 113 - 164. 
2 Pogg. Annal. Bd. 160, p. 264. ti 
3 Wied. Annal. Bd. 14, p. 13. 7 orp? 
4 According to the Chemical News, Vol. 69, No. 1790, p. 123-—~"" 
and Rodgers in the Bakerian Lecture of the Royal Society, give Fer 
for preferring Slotte’s formula n= e/(1 +br)". I have not ot 
paper. 
5 Loe. cit., p. 17. 
