| Morphine—Solid | |
|---|---|
| Treated with strong nitric acid. | Dissolves with effervescence and |
| the production of ruddy fumes, | |
| forming a rich orange-coloured | |
| solution not changed by the | |
| addition of stannous chloride. | |
| Mixed with a little iodic acid | A blue colour, due to the |
| and starch paste. | liberation of iodine. |
| Dissolved in cold strong | Bright-green colour. |
| sulphuric acid, and a drop of | |
| strong solution of bichromate | |
| of potash added. | |
| Rubbed with sulphomolybdic acid | A violet colour changing to |
| (Frohde‘s reagent). | green, and then sapphire-blue. |
| Morphine and Meconic Acid in Solution | ||
|---|---|---|
| Morphine. | Meconic Acid. | |
| Tested with litmus paper. | Slightly alkaline. | Very distinctly acid. |
| A little perchloride | An inky-blue colour, | Deep red colour, not |
| of iron, rendered | destroyed and changed | easily destroyed by |
| of nearly neutral | to orange-red by | a solution of |
| as possible. | nitric acid. | corrosive sublimate or |
| dilute mineral acids. | ||
The characteristic tests for morphine are its reactions with nitric acid, iodic acid and starch, and perchloride of iron. The reaction with the perchloride of iron is also characteristic of meconic acid. This last-mentioned test is a very conclusive one for meconic acid, when certain precautions are taken; for the property of striking a deep red with a persalt of iron is shared equally by sulphocyanides and alkaline acetates. The colour produced by sulphocyanic acid is instantly bleached on the addition of corrosive sublimate. The question thus lies between acetic and meconic acid. To distinguish the one from the other, the solution to be tested should be boiled for a short time after the addition of a few drops of sulphuric acid. Any acetate present is decomposed and the acetic acid is expelled by the boiling; so that if, after allowing the solution to cool, it still gives the red colour with perchloride of iron, the reaction may be taken as conclusive of meconic acid. By these means morphine and meconic acid may be detected in porter and other liquids.
Table showing the Characters and
Tests of the Following Poisons
| Morphine. | Strychnine. |
|---|---|
| 1. Crystallises in colourless | 1. Crystallises in white |
| transparent prisms, belonging | four-sided prisms, terminated |
| to the trimetric system. | by four-sided pyramids. |
| 2. Sulphuric acid and | 2. Treated with cold sulphuric |
| bichromate of potash give | acid, no reaction; on |
| a bright-green coloration. | the addition of a crystal of |
| potassium bichromate, an | |
| intense purple colour is | |
| produced, becoming | |
| crimson and then light red | |
| 3. Strong colourless nitric acid, | 3. Strong nitric acid usually |
| added freely to a cold | produces a yellow or |
| solution, produces a deep | yellow-brown colour. |
| orange-red coloration, not | |
| changed by stannous chloride. | |
| Brucine. | Narcotine. |
| 1. Crystallises in oblique rhomboidal | 1. Crystallises in right rhombic |
| prisms, sometimes agglomerated | prisms, or in needles |
| mushroom-like heads. | grouped in bundles. |
| 2. Sulphuric acid gives a | 2. Sulphuric acid a bright |
| rich rose-pink tint; on the | sulphur-yellow colour, |
| addition of potassium | potassium bichromate added a |
| bichromate, none of the | green colour as with morphine, |
| reactions of strychnine | but slower in production. |
| are observed. | |
| 3. Strong nitric acid produces a | 3. Strong nitric acid forms |
| blood-red colour, changed | a colourless fluid, becoming |
| after warming and diluting | yellow on heating. |
| with distilled water to purple | |
| by stannous chloride; | |
| ammonium sulphide gives | |
| a similar but less marked | |
| reaction. Excess of stannous | |
| chloride discharges the | |
| blood-red colour in the cold. |
CHAPTER VIII
NARCOTIC POISONS
Somniferous
OPIUM
Opium is the inspissated juice of the Papaver somniferum, the garden or opium poppy. The plant is a native of Egypt and Syria, cultivated in England.
Opium is sometimes taken in its crude state as a poison, but more frequently one of its preparations is thus employed—notably the tincture, better known as laudanum.