1500 
From these experiments the mean specifie heat of the p-form can 
therefore be calculated, and besides extrapolation to the transition 
point yields the heat which is liberated when ammoniumchloride is 
transformed at the transition temperature and then cooled. The differ- 
ence between the two values found by extrapolation yields the 
required heat of transformation at the transition point. 
TABLE 5: 
eee 
nnee | Tempe: | | | an | ke EN Heat 
Ne ture bol | calor | Heat \tegiass) NHG | NMC Pergramme 
157.7 13.5 A fad 187.8 — 60.1 | 3.600 | —16.69 
2 | 158.25 13295 115.0 lied — 56.7 | 3.487 | —16.26 
Sia ee158.9 14.5 116.7 174.3 — 57.6 | 3.603 —15.99 
4 159.25 jg) | 115.9 171.0 — 55.1 | 3.456 —15.94 
5 157.95 16.7 105.6 169.2 —- 63.6 | 3.819 —16.40 
6 158.7 | 16.0 PIES 166.6 — 55.3 | 3.556 —15.55 
i 178.35 17.6 170.4 194.7 — 24.3 3.771 = 6.44 
8 179.1 | 15.45 187.3 206.9 — 19.6 3.186 | — 6.15 
9 179.25 | 15.35 | 203.89 22185 — 23.7 3.411 | — 6.83 
10 179255) | 1525 | 191.0 | 212.8 | — 21.8 3.620 — 6.02 
11 195.2 16.1 321.8 250.5 + 71.3 3.742 | +19.05 
12 | 195.5 | 15E 327.6 256.6 + 71.0 3.714 | +19.12 
13 | 195.5 | 15.75 | 297.9 | 231.7 | + 66.2 | 3.424 | +19.33 
14 | 211.45 | 16.35 | 382.5 280.0 +102.5 4.080 | +25.12 
15 | 211.55 | 15.95 | 348.8 | 259.8 | + 89.0 | 3.742 | 423.718 
16) Bots | 6.3 | 359.3 | 260.2 | + 99.1 | 3.931 | 425.21 
The tables 5 and 6 yield the results obtained; in table 6 the 
mean values have been recorded of the experiments, which have 
been carried out under nearly comparable circumstances. For the 
extrapolation to the transition point also the temperature of the 
calorimeter has been extrapolated. 
It is clear that a correction can be avoided in this way which is 
difficult to determine experimentally. If namely in two experiments 
the temperature of heating is the same, but the temperature of the 
calorimeter different, a correction is to be applied for this difference 
