| On boiling the filtered solution, to expel the ammonia, and evaporating the liquid, crystals of narceine are gradually deposited. |
| If on a saturated solution of narceine a particle of iodine is strewn, fine needle-like grey crystals form around the iodine. |
| The precipitates produced in solutions of narceine and codeine are crystalline and very characteristic. |
| Papaverine, laudanosine, narcotine, and narceine are four other alkaloids found in opium. |
