The chronic and nervous diseases of children, which are so numerous and frequently fatal, are, I believe, frequently occasioned by worms. There is no great danger, therefore, of doing mischief, by prescribing anthelmintic medicines in all our first attempts to cure their chronic and nervous diseases.

I have been much gratified by finding myself supported in the above theory of worm-fevers, by the late Dr. William Hunter, and by Dr. Butter, in his excellent treatise upon the infantile remitting fever.

I have taken great pains to find out, whether the presence of the different species of worms might not be discovered by certain peculiar symptoms; but all to no purpose. I once attended a girl of twelve years of age in a fever, who discharged four yards of a tænia, and who was so far from having discovered any peculiar symptom of this species of worms, that she had never complained of any other indisposition, than now and then a slight pain in the stomach, which often occurs in young girls from a sedentary life, or from errors in their diet. I beg leave to add further, that there is not a symptom which has been said to indicate the presence of worms of any kind, as the cause of a disease, that has not deceived me; and none oftener than the one that has been so much depended upon, viz. the picking of the nose. A discharge of worms from the bowels, is, perhaps, the only symptom that is pathognomonic of their presence in the intestines.

I shall now make a few remarks upon anthelmintic remedies.

But I shall first give an account of some experiments which I made in the year 1771, upon the common earth-worm, in order to ascertain the anthelmintic virtues of a variety of substances. I made choice of the earth-worm for this purpose, as it is, according to naturalists, nearly the same in its structure, manner of subsistence, and mode of propagating its species, with the round worm of the human body.

In the first column I shall set down, under distinct heads, the substances in which worms were placed; and in the second and third columns the time of their death, from the action of these substances upon them.

I. Bitter and astringent substances.Hours.Minutes.
Watery infusion of aloes248
—— of rhubarb130
—— of Peruvian bark130
II. Purges.
Watery infusion of jalap1—
——— bear's-foot117
——— gamboge1—
III. Salts.
1. Acids.
Vinegar—1½ convulsed.
Lime juice— 1
Diluted nitrous acid— 1½
2. Alkali.
A watery solution of salt of tartar—2 convulsed, throwing
up a mucus on
the surface of
the water.
3. Neutral Salts.
In a watery solution of common salt—1 convulsed.
— of nitre—ditto.
— of sal diuretic—ditto.
— of sal ammoniac— 1½
— of common salt and sugar.— 4
4. Earthy and metallic salts.
In a watery solution of Epsom salt— 15½
— of rock alum— 10
— of corrosive sublimate—1½ convulsed.
— of calomel— 49
— of turpeth mineral—1 convulsed.
— of sugar of lead— 3
— of green vitriol— 1
— of blue vitriol— 10
— of white vitriol— 30
IV. Metals.
Filings of steel— 2½
Filings of tin1—
V. Calcareous Earth.
Chalk2—
VI. Narcotic Substances.
Watery infusion of opium—11½ convulsed.
—— of Carolina pink-root— 33
—— of tobacco— 14
VII. Essential Oils.
Oil of wormwood—3 convulsed.
— of mint— 3
— of caraway seed— 3
— of amber— 1½
— of anniseed— 4½
— of turpentine— 6
VIII. Arsenic.
A watery solution of white arsenicnear 2—
IX. Fermented Liquors.
In Madeira wine—3 convulsed.
Claret—10
X. Distilled Spirit.
Common rum—1 convulsed.
XI. The Fresh Juices of Ripe Fruits.
The juice of red cherries— 5½
——— of black do.— 5
——— of red currants— 2½
——— of gooseberries— 3½
——— of whortleberries—12
——— of blackberries— 7
——— of raspberries— 5½
——— of plums—15
——— of peaches—25
——— of water-melons, no effect.——
XII. Saccharine Substances.
Honey— 7
Molasses— 7
Brown sugar—30
Manna— 2½
XIII. In Aromatic Substances.
Camphor— 5
Pimento— 3½
Black pepper—45
XIV. Foetid Substances
Juice of onions— 3½
Watery infusion of assafœtida—27
—— Santonicum, or worm seed1—
XIV. Miscellaneous Substances.
Sulphur mixed with oil2—
Æthiops mineral2—
Sulphur2—
Solution of gunpowder— 1½
—— of soap—19
Oxymel of squills— 3½
Sweet oil230

In the application of these experiments to the human body, an allowance must always be made for the alteration which the several anthelmintic substances that have been mentioned, may undergo from mixture and diffusion in the stomach and bowels.