or A STTESTAXCE TvESElirBtTXG QUININE. 
37 
destruction and removal through the action of marsh miasm give rise to ague? Does 
quinine cure ague by furnishing a substance which retards the changes which go on in 
the textures ? and in the well-known property of arsenic to preserve organic substances 
have we also the explanation of its power in curing ague ? 
2. If the chemical circulation can carry alkaloids even into the non-vascular tissues, is it 
not reasonable to suppose that medicines pass through the blood and act on the textures ? 
and is it not most probable that they take part in every chemical change that occurs outside 
the blood-vessels, as well as in the blood itself? Still further, may we not expect that among 
the multitudes of new substances which synthetical chemistry is now constantly forming, 
some medicines may be discovered which may not only have power to control the excessive 
chemical changes of the textures in fevers and inflammations, but may be able to remove 
the products of insufficient chemical action even in those diseases which affect the non- 
vascular textures, as, for example, in cataract and in gout ? 
It remains that I should in a very few words tell you what was already known regard¬ 
ing this fluorescent substance, and on the rate of passage of alkaloids into and out of the 
body, before we begin our work. 
In 1845, Professor Briicke stated that the lens absorbed the blue rays of light to a very 
great extent, and that the cornea and aqueous humour did so to a less extent. In 1855, 
Professor Helmholtz examined for fluorescence the retina of the eye of a man who had 
been dead for eighteen hours. The first experiment showed that it was very feebly 
fluorescent. The colour of the light dispersed through the retina he found greenish- 
white. 
In 1858, M. Jules Eegnauld, using sunlight, found in man and the mammifera that 
the cornea fluoresced in a very slight degree. In the sheep, dog, cat, and rabbit, the 
crystalline lens possessed in the highest degree fluorescent properties. In these animals, 
and also in many birds, the central part of the lens, preserved by desiccation at a low tem¬ 
perature, retained this property. The central portion of the crystalline of many vertebrata 
and mollusca he found almost entirely without fluorescence. The vitreous humour pos¬ 
sesses only a very feeble fluorescence, due to the hyaline membrane. The retina pos¬ 
sessed a certain fluorescence which was not all comparable in intensity to that of the 
crystalline lens. 
In 1859, L. Setschenow, of Moscow, a pupil of Helmholtz, at his request, experimented 
on the eyes of men and rabbits. The fresh retina showed the same phenomenon as the 
dead human retina. It diffused a greenish-white light, which, examined by a prism, 
gives a spectrum in which the red is wanting. The vitreous humour in a thin glass 
vessel showed only traces of fluorescence. The lens, on the contrary, fluoresced very 
strongly, the colour of the dispersed light being white-blue, exactly like quinine, only the 
quinine was a little stronger. Examined by a prism, the dispersed light gave a spectrum 
in which the red was wanting, and in which the blue tone predominated. The fluo¬ 
rescence begins, as in quinine solutions, between G and H, and is strongest at the outer 
edge of the violet rays, and extends into the ultra violet to the same distance in the case 
of the lens as in the case of the quinine solution. 
When the cornea was cut out, it fluoresced much feebler than the lens ; the aqueous 
humour did not fluoresce at all. 
The appearances in the three last media, he says, can be shown with the greatest ease, 
even in the eye of the living man. When the eye is brought into the focus of the ultra 
violet rays, immediately the cornea and the lens begin to glimmer with a white-blue 
light. The cornea of the living eye is much more fluorescent than when dissected out, 
probably from the loss of transparency, consequent on contraction of the texture, and 
from evaporation. 
Professor Bonders has carefully investigated the time in which atropine and Calabar 
bean act on the iris in man. 
A solution of atropine dropped on the cornea in fifteen minutes begins to act, and 
attains its maximum in from twenty to twenty-five minutes. In forty-two hours the 
pupil is rather smaller, and even after thirteen days the pupil was not quite its natural 
size. 
The fluid extracted from the aqueous humour, injected into another eye, caused dila¬ 
tation of the pupil. 
A solution of Calabar bean began to act in from five to ten minutes ; attained its 
maximum in from thirty to forty minutes. At the end of three hours it began to dimi¬ 
nish, and disappeared entirely in from two to four days. 
