The stomach-pump ought only to be used in those cases of poisoning by opium, or alcohol, or other narcotics, in which the stomach and nervous system are rendered so insensible that vomiting cannot be excited. Many people speak of a stomach-pump, as if its use was a very simple affair, whereas, it is well known to be a very dangerous instrument. "It is a well established fact, that a tube may sometimes be passed into the trachea of a sensible person without creating any peculiar sensation, or exciting cough; but, if the patient be insensible, that accident will be much more likely to happen. In fact, a case is on record in which a meddling surgeon, with more zeal than knowledge, did actually pass the tube down the windpipe, and inject the lungs with chalk mixture. And Sir Charles Bell tells us, that he has seen on dissection both lungs filled with broth, which was intended to be injected into the stomach. Again it is known that in one case the mucous membrane of the stomach was sucked into the holes of the tube, and torn into strips, a thing likely to happen if the stomach is pumped too empty. Besides this, artificial evacuation of the stomach is by no means so efficacious as free vomiting, assisted by plenty of diluents. Lumps of arsenic were left in the stomach, in the very case just cited, in which the stomach was torn."

It is usual to place a gag in the patient's mouth,, having a hole for the tube to pass through, in order that it may not be compressed by the teeth. Before pumping out the contents of the stomach, one or two pints of water should be injected into it, and care should be taken not to withdraw quite as much as was injected. More water should then be thrown in, and the process should be repeated till it returns colourless.