The symptoms caused by the irritating poisons, taken internally, are chiefly those of violent irritation and inflammation of one or more divisions of the alimentary canal.
The mouth is frequently affected, especially when the poison is easily soluble, and possesses a corrosive as well as irritating power. The symptoms referrible to the mouth are pricking or burning of the tongue, and redness, swelling and ulceration of the tongue, palate, and inside of the cheeks.
The throat and gullet are still more frequently affected; and the affection is commonly burning pain, sometimes accompanied with constriction and difficulty in swallowing, and always with redness of the visible part of the throat and gullet.
The affection of the throat and mouth precedes every other symptom when the poison is an active corrosive, and more particularly when it is either a fluid poison or is easily dissolved. Nay, sometimes burning pain of the mouth, throat, and gullet occurs during the very act of swallowing.—On the contrary if the poison is soluble with difficulty, and is only an irritant, not a corrosive, and still more if it is only one of the feebler irritants, the throat is frequently not affected sooner than the stomach, occasionally not at all.
The stomach is the organ which suffers most invariably from the operation of irritant poisons. The symptoms referrible to their operation on it are acute and general burning pain, sometimes lancinating or pricking pain,—sickness, vomiting, tenderness on pressure, tension in the upper part of the belly, and occasionally swelling. Of these symptoms the sickness is generally the first to develope itself. In the instance of corrosive irritants pain commonly commences along with it. The matter vomited is at first the contents of the stomach, afterwards tough mucus, streaked often with blood and mingled with bile, frequently clots of purer blood. The powerful corrosives affect the stomach the moment they are swallowed; irritants which are either liquid or very soluble also affect it very soon; but the more insoluble irritants, such as arsenic, generally do not begin to act till half an hour or even more than a whole hour has elapsed.—The stomach may be affected without any other part of the alimentary canal participating in the injury; but much more frequently other parts suffer also, and in particular the intestines.
The action of irritant poisons on the intestines is marked by pain extending over the whole belly, sometimes even to the anus. This pain, like that of the stomach, is often a sense of burning; but it is also frequently a pricking or tearing pain, and still more frequently a twisting, intermitting pain like that of colic. It is seldom attended with much swelling, but often with tension, and tenderness of the whole belly; and at times the inflammatory state of the mucous coat of the intestines is clearly indicated by excoriation of the anus and prolapsus of the rectum, which is of a bright red colour. The pain of the bowels is most generally attended by purging, rarely with constipation, frequently with tenesmus. The matter discharged, after the alimentary and feculent contents have passed, is chiefly a mucous fluid, often abundant, often also streaked with blood or mixed with considerable quantities of blood. In some cases the intestines are affected when no other part of the alimentary canal suffers, not even the stomach. But much more generally the stomach and intestines are affected together.
In a few very aggravated cases of poisoning with the irritants the whole course of the alimentary canal, from the throat to the anus, is affected at one and the same time.
The symptoms now briefly enumerated are accompanied in almost every instance with great disturbance of the circulation—quick, feeble pulse—excessive prostration of strength,—coldness, and clammy moisture of the skin.
The other symptoms, which are often united with the preceding, do not belong to the irritants as a class. Perhaps, however, among the symptoms of the class may be mentioned those of irritation and inflammation of the windpipe and lungs, and those of irritation in the urinary organs. A great number of the irritant poisons cause hoarseness, wheezing respiration, and other signs which indicate the spreading of the inflammation of the throat to the windpipe: some likewise cause darting pains throughout the chest: and not a few are very apt to cause strangury and other signs of inflammation of the urinary passages.
Of the effects of the irritants when applied externally little need be said at present. Their most striking external symptoms will be noticed under the head of one of the orders of this class, the vegetable acrids. In the chapter on the local action of poisons some account was given of the several effects which are produced by the application of poisons to the skin. It is there stated that some produce merely redness, that others cause blistering, that others bring out a crop of deep-seated pustules, that others corrode the tissues chemically, and so give origin to a deep slough, and that others excite spreading inflammation of the cellular tissue under the skin and between the muscles.