9. Conia. Conia is best obtained from the fruit, before it has become dry. it may be obtained by distilling a mixture of an alcoholic extract of the seeds with strong solution of potassa. The acid of the native salt of conia is seized by the potassa, and the liberated alkaloid rises with the vapour of the water, and floats upon its surface in the receiver after condensation.

Properties

Conia is a yellowish liquid, with the aspect of an oil, lighter than water, of a strong, penetrating, mice-like odour, and a very acrid benumbing taste. it is very volatile, and rises with the vapour of water when boiled with it; but its point of ebullition when alone is 370°. it is slightly soluble in water, and freely so in alcohol, ether, and the fixed and volatile oils. it unites with one-third of its weight of water to form a hydrate, which has a strong alkaline reaction. With the dilute acids it forms soluble salts, but is decomposed by the stronger acids. its vapour produces white fumes with that proceeding from liquid muriatic acid. Tannic acid forms with it an insoluble compound, and therefore precipitates it from its solutions. When exposed to the air, it is gradually decomposed, being converted into a resinous matter and ammonia. This change takes place rapidly when it is heated. it consists of nitrogen, carbon, and hydrogen.

Effects on the System

These appear to be identical with the effects of hemlock itself. it is an energetic poison. A single drop of it introduced into the eye of a rabbit, killed the animal in nine minutes; and three drops in the eye of a stout cat proved fatal in a minute and a half. it is stated not to dilate the pupils when thus applied. Dr. Christison observed that it first paralyzed the voluntary muscles, then those of the chest and abdomen, and finally the diaphragm, producing death from asphyxia. Sometimes there were tremors and convulsive twitchings of the limbs. Sensation did not seem to have been destroyed, so long as observation could be made on this point. The alkaloid is locally irritant.

Therapeutic Application

Conia has not been introduced into general use; but has been employed by some practitioners with signal advantage.* Dr. Spongier, of Herborn, gave it to a child a year old, affected with hooping-cough, in the dose of one-sixteenth of a grain every six hours, with the asserted effect of curing the disease in ten days. (Ann. de Thérap., 1853, p. 73.) Fronmuller considers it as having all the powers of hemlock, without its uncertainty. He has found it specially useful in scrofula, and more particularly in scrofulous ophthalmia, when attended with excessive sensibility, spasm of the eyelids, photophobia, shedding of tears, and severe pains. He dissolves 3 or 4 drops of conia in 15 grains of alcohol and 300 of distilled water, and gives from 15 to 30 drops, in a cup of sweetened water, three times a day. The worst effect he has witnessed has been sometimes a little headache and vertigo, though he has continued the medicine for months. (Trousseau and Pidoux, Trait, de Thérap., 4e ed., II. 118.) Professor Mauthner, of Vienna, has found the topical use of the remedy extremely beneficial, in the same scrofulous affections of the eyes, with photophobia and spasmodic closure of the lids. He dissolves half a grain in a drachm of almond oil, and pencils the eyelids with the solution two or three times a day. The most obstinate cases yield in a week or two. He finds the same remedy useful in indolent glandular swellings of the neck. (See Am. Journ. of Med. Sci., Jan. 1855, p. 253.) Professor Muraw-jeff, a Russian physician, has used conia externally, with much success, in not a few diseases. He has employed it successfully in chronic cutaneous eruptions, as lichen, prurigo, psoriasis, eczema, acne, and por-rigo or favus. One drop of it, in the hollow of a carious tooth, allays the pain more rapidly and effectually than chloroform. in neuralgia and syphilitic pains it effects radical cures. it is beneficial, also, as an anodyne, in chronic synovitis, scrofulous and rheumatic inflammation of the eyes, and scrofulous and cancerous ulcers; and relieves the pain of wounds. in affections of the skin, the Professor uses an ointment made with from 12 to 24 drops of conia and an ounce of simple ointment or cold cream. in neuralgia he first washes the part with alcohol, and then applies three or four drops of the conia. in both instances he covers the part after the application with oiled silk and a bandage. in cancer, he applies the liquid mixed with mucilage. For a collyrium, he adds from 1 to 3 drops to a fluidounce of weak mucilage of quince seeds, and as an enema gives two or three drops in emulsion of starch. {ibid., July, 1855, p. 187.) From the above data, I should infer that half a drop might be given to an adult for a commencing dose.

* Experiments with conia, made on the human subject, under the superintendence of Dr. Schroff, furnished the following results. The dose taken varied from the fourteenth of a drop to two drops, and was dissolved in thirty drops of alcohol. The first impression was that of a strong irritant to the mouth and fauces; but the tongue soon lost its sensibility, as if paralyzed. in about three minutes, heat in the head and face, with feelings of fulness, weight, and pressure, were experienced from the larger doses. To these sensations, giddiness, mental confusion, sleepiness, and general uneasiness were soon added. The sight was indistinct, the pupil dilated, the hearing obtuse, and the touch uncertain, with a feeling of formication. There were also general muscular weakness, coldness and blueness of the hands, pale and sunken countenance, and diminished frequency of pulse, following an increase of a few beats in the minute. Nausea and efforts to vomit generally occurred, and in one instance positive emesis. The secretion of urine was not increased. Under large doses the hands became moist. The effects continued in a greater or less degree to the following day. (See Am. Journ. of Med. Sci., N. S., XXXII. 478.)- Note to the second edition.