88 On Coloured Vision produced by Santonine. 



ON COLOURED VISION PRODUCED BY SANTONINE. 



BY DR. PHIPSON, F.C.S., LONDON, ETC. 



In my work. Phosphorescence ; or, the Emission of Light by 

 Minerals, Plants, and Animals, I have described (pp. 162 — 164) 

 a series of rather curious phenomena, under the designation of 

 Subjective Phosphorescence. They occur whenever the optic 

 nerve receives the slightest shock, or an injury of any kind ; 

 they present themselves in certain diseases, such as typhus 

 fever, measles, etc. ; they are determined by sudden increase of 

 circulation, by the action of a weak electric current through the 

 eye, by the use of certain narcotic medicines, etc. In these 

 cases we see a more or less vivid production of light, which is 

 all the more interesting as it occurs within ourselves, establishing 

 the fact that light (in these circumstances certainly) is produced 

 by a vibratory motion of matter. It shows itself either in form 

 of revolving specks, radiated lines, or the arborescent figures 

 described by Purkinje, etc. In the present paper I have to 

 treat of another set of physiological phenomena quite as inte- 

 resting as those just referred to, and bearing a certain relation 

 to them. I allude here to the production of coloured vision by 

 means of a substance called Santonine, a crystalline principle 

 which exists in the plants of the wormwood tribe {Artemisia), 

 and in the semen contra of pharmaceutists. 



" Semen contra vermes," or simply u semen contra," is the 

 name given to the mixed flowers and seeds of Artemisia 

 judaica, L., a plant native of Arabia and North Africa. In 

 commerce there are various kinds of semen contra. The French 

 and Belgians call it sometimes Sementine or Barbotine. Arte- 

 misia contra is another plant which furnishes it. These plants 

 are met with also in Tartary and Persia, and are cultivated in 

 our gardens. The semina santonici, or santonicum of pharmacy, 

 is a powdery substance, with a strong aromatic odour and very 

 bitter taste, resulting from the breaking up or coarse pulveriza- 

 tion of the flower-heads and stalks adjoining ; the flowers being 

 partly gone to seed, the whole is a mixture of seed, flower stalk, 

 and leaflets. This product is taken internally to kill intestinal 

 worms, at a dose of about one drachm in powder alone, with 

 honey or otherwise, repeated two or three times a day ; and 

 when it has been continued for some days, a strong purgative 

 is administered, which completes the cure. 



Artemisia absinthium, another plant of the same family, 

 and, in general, all the Wormwood tribe, possess, more or less, 

 the same medical properties. In England we have a number 

 of Artemisia, known as wormwood, southernwood, and mug- 



