Give the chemical reaction for the detection of nitrogen in an organic compound using the Lassaigne's test.

(N/A) The detection of nitrogen involves the following steps:
$1$. Fusion with sodium metal: $N + C + Na \longrightarrow NaCN$
$2$. Formation of ferrocyanide: $6 CN^{-} + Fe^{2+} \longrightarrow [Fe(CN)_{6}]^{4-}$
$3$. Formation of ferric ferrocyanide (Prussian blue): $4 Fe^{3+} + 3 [Fe(CN)_{6}]^{4-} \cdot x H_{2}O \longrightarrow Fe_{4}[Fe(CN)_{6}]_{3} \cdot x H_{2}O$