Meanwhile it is sufficiently clear that nitrogen deviates from the 
behaviour of monatomie solid substances such as copper, lead etc. 
In particular the specific heats at the liquid hydrogen temperatures, 
at which CC, very probably has still small values, point in this 
direction. The same follows also when 4 is calculated from LiNpr- 
MANN’s formula (Comm. N°. 147a § 5): £,=2,81 , 7;=63 , vu = 
14,01 ae A 
SE according to Dewar at — 252,5° C. give 6 = 120, ie. a 
value which is considerably too high. 
Hence presumably nitrogen is in the solid state also di-atomic *), 
Le. the crystal space lattice *) is composed of 2 point systems placed 
one inside the other in an analogous way as for instance the space 
lattice of rhombic sulphur is built up from 8 interpenetrating (rhom- 
bic) point systems, in such a way that a new frequency is intro- 
duced by the vibrations of the two point systems with respect to 
each other. 
§ 5. Specific heat of liquid nitrogen. 
With the aid of the apparatus described in $ Ll some measurements 
were also made of the specific heat of liquid nitrogen. 
When the vapour pressure of the liquid attains an appreciable 
value, a correction has to be applied for the evaporation caused by 
the temperature increase in the calorimetric experiment. For this 
purpose the increase of pressure was read on the safety tube v. 
The quantity which has vaporized then follows from the approximately 
known volume between 4, Á the solid nitrogen in # and the 
10 
mercury in the safety tube v. This correction was always small: 
at the highest temperature it amounted only to 0.8°/, of the heat 
supplied. 
In table Il the data concerning liquid nitrogen are given’). 
1) This conclusion was already drawn by Neryst and Linpemann, Berlin Sitz. 
Ber. 1912, p. 1170 from the low triple point of nitrogen in connection with its 
possessing subsidiary vaiencies. 
2) For both the modifications (p. 1251 note 4). As according to W. Want. Proc. 
Roy. Soc. A 87 (1912), p. 371, ZS. physik. Chem. 84 (1913), p. 101, nitrogen 
below the triple point at first crystallizes in the cubic system, those point systems 
must be cubic for the modification which is stable at the higher temperatures. 
3) Strictly speaking the values given in table II for the specifie heat and the 
atomic heat are valid for the liquid under the pressure of its saturated vapour; 
within the degree of accuracy of the measurements they may be considered to 
coincide with cp, and Cp respectively. 
