In carbylamine reaction amine is treated with chloroform in presence of sodium hydroxide to produce isocyanide which has offensive / foul smell is called carbylamine reaction or isocyanide test.
This reaction is used to distinguish PRIMARY AMINE from SECONDARY / TERTIARY AMINE.
The isocyanide is poisonous gas, and Methyl isocyanide (CH3NC) that is also called MIC gas was leaked in Bhopal, Madhypradesh state of India from a multinational factory, consequently a large number of people were died and injured and have been suffering till now.
CHEMIGOD 