A. Diaphoresis, with erythema of the chest, 1, 351. Diaphoresis, 6, 605; Jorg, 17, 417; 22, 1: 100; 54, 1: 383. Pruritus, 48, 126.

Prickings in the skin, 22, 1: 100. Formication, 32, 2: 47; 34, 1: 162.

B. The flowers, after six or eight hours, cause itching, burning, and slight redness, 36, 1: 229. Erysipelatous, or peculiar violet-colored eruption, not produced when an aqueous preparation is used, but only with the alcoholic, 2, 306. Itching, congestion, papules, vesicles, excoriations, crusts and scales, White, 115, '75, 61. Erythema, vesicles, pustules, Earle, 186, Sept. '77; 209. Redness, papules, vesicles, and excoriations, Harnden, 152, Dec. '78, 357. Redness and vesicles, 202; 204, (H.G.P.) Purpura, Schmidt, 32, 2: 54.

C. and D. Urticaria, 208.

D. Pernio, Purdon (142, '65), 44, 106. Eczema, Piffard, 143, Oct. 26, '78.

Remarks

The officinal preparations of arnica are: Extractum Arni-cor; T'inctura Arnicae; and Emplastrum Arnicoe, all of which are made from the flowers. The occurrence of erysipelatoid inflammation of the skin following local applications of the tincture of arnica has been noticed for many years, and is usually attributed to some irritant ingredient pertaining to the arnica. It is possible that this is not the case, but that the irritant action is due to a foreign body accompanying the arnica flowers, namely the larvae of the Atherix maculatus. As early as 1811, Mercier * noticed that the ingestion of preparations of arnica flowers was sometimes followed by symptoms of grave irritation. On further investigating the matter he found that the flowers were frequently infested with the eggs, larvae and remains of an insect. These he isolated and from them obtained an extract which he found acrid and irritating. He believed that the untoward effects of arnica are thus caused, as they were not observed when flowers free from insects were employed. Later, Buch-ner + also found the young caterpillars (raupen), and at his instance Prof. Oppel studied their development and ascertained that they were the young of the Atherix maculatus. In examining arnica flowers the writer has met with the insect remains referred to, in some specimens quite abundantly. The puppae and the adult fly (life size and magnified) will be found figured by Mann,++ in company with his plate of the arnica plant.

All of the cases of arnica poisoning that have fallen under my own notice have followed the use of the officinal tincture of the flowers; on the other hand, I have very frequently employed a tincture of the root without accident. If a wider experience confirms the suspicion that the atherix and not the arnica is really the cause of the local irritation, the use of preparations of the root should supplant that of the flowers.