( 399 ) 
field-range. The full communication of the results obtained would 
require many tables and curves; we therefore draw attention to the 
principal points only. 
Specific susceptibility x ) at 18°. The values found lie between — 2 
and -{- 5 (amorphous carbon and palladium respectively). It cannot 
be maintained that the positive paramagnetic values are on the whole 
larger than the negative diamagnetic ones. Oxygen alone forms an 
exception with a value of about 100 the value for manganese was 
approximately 10; this contained, however, 7*% of iron. 
Ccrie had already pointed out the influence of allotropy in the 
case of phosphorus and antimony, and also that there is no such 
influence with sulphur, though it is so well-known for its polymor¬ 
phous properties. A difference was shown to exist between diamond 
( — 0,49) and amorphous carbon ( —2,02); silicium crystalline (0,12) 
and amorphous (— 0,14); and especially between common tetragonal 
tin (+0,03) and grey tin (— 0,29;. In the case of tin, the first — 
the tetragonal — was Kahlbacm’s very pure electrolytic material; 
it was afterwards inoculated with a small quantity of grey tinpest, 
kindly sent by Prof. Cohen from the stores of the van’t Hoff Laboratory. 
For weak fields indium seemed to be paramagnetic; in a field of 
7 Kgs. the value of the susceptibility passed through zero and became 
negative, doubtless in consequence of 0,013°/,, iron : this phenomenon 
is of no consequence because it is also discovered in complicated 
substances such as certain kinds of porcelain, glass, etc. 
Notwithstanding many omissions, it was still possible to follow the 
general course of the curve ±= funct. (a); the curve appears to be 
rather intricate, but still shows a distinct relation to the periodic 
system. According to the arrangement of Mendelejeff-Brauner’s table, 
the rows (1, 2, 3, 4), (5, 6, 7, 8), and (9,10,11, 12) each form a division 
I, II, III in which the shape of the curve repeats itself in a peculiar 
way. At the junction of I and II Cr, Mn, Fe, Co, Ni lie on a 
positive maximum; between II and III, in the same way, the “rare” 
metals: within I, II and III the diamagnetic negative peaks are 
occupied by the similar pentavalent elements P, Sb and Bi of the 
fifth group (3 d , 7 th , 11 th row). In more than one respect further 
magnetic analogies of secondary importance exist, which, however, 
must be left unmentioned in this communication. 
Susceptibility at high tempei'atures. As a rule the path of the curve 
X == funct. {0) for any substance proved to be the same when the 
temperature was increased or afterwards decreased; certain deviations 
probably depend on a change of condition of the iron present afte r 
l ) Everywhere below expressed in millionths. 
