The kinetics of the thermal decomposition of benzylamine were studied by a flow method using toluene as a carrier gas. The decomposition produced NH
3
and dibenzyl in a molar ratio of 1:1, and small quantities of permanent gases consisting mainly of H
2
. Over a temperature range of 150° (650 to 800° C) the process was found to be a homogeneous gas reaction, following first-order kinetics, the rate constant being expressed by
k
= 6 x 10
12
exp (59,000/
RT
) sec.
-1
. It was concluded, therefore, that the mechanism of the decomposition could be represented by the following equations: C
6
H
5
. CH
2
. NH
2
→ C
6
H
5
. CH
2
• + NH
2
•, C
6
H
5
. CH
3
+ NH
2
•→ C
6
H
5
. CH
2
• + NH
3
, 2C
6
H
5
. CH
2
•→ dibenzyl, and the experimentally determined activation energy of 59 ± 4 kcal./mole is equal to the dissociation energy of the C-N bond in benzylamine. Using the available thermochemical data we calculated on this basis the heat of formation of the NH
2
radical as 35.5 kcal./mole, in a fair agreement with the result obtained by the study of the pyrolysis of hydrazine. A review of the reactions of the NH
2
radicals is given.