Mr. Wharton Jones, in his Astley Cooper Prize Essay, states that he has found the effects of medicinal solutions on the capillaries in the web of a frog's foot to be very various. For even a solution of Sulphate of Copper has been known to cause dilatation, and one of Atropia to produce constriction; though the former is an astringent; and the latter a paralyzer. So that the vessels are not nearly so much under the influence of such agencies as Dr. Billing would seem to imagine. In these experiments the solutions were concentrated, and applied directly. But in the cases in point we might have two or three grains of Iodide of Potassium, one-tenth of a grain of Arsenite of Potash, or one-twentieth of a grain of Bichloride of Mercury, diluted down by about twenty pounds of blood, and extended through many miles of capillary tubes! And if simple contraction of the capillaries were required, surely Astringents, which are known to effect this, should be the most useful of all these medicines. But we do not find it to be so. Further, this idea must include a virtual denial of the causation of blood disorders by special morbid agencies.
Such are the grounds upon which is founded a denial of the existence of specific medicines—i.e. of remedies which are of particular or special use in one or more disorders. Is it reasonable to deny that Mercury is of particular use in Syphilis? that Iodide of Potassium exerts a special influence over secondary forms of the same malady? that Iodine and Potash are each peculiarly adapted to scrofulous cases? or that Colchicum will often stop a fit of the Gout when other medicines have failed to relieve it? If we cannot deny it, we must admit such actions to be in some degree specific. To adopt this term is to a certain extent to confess our ignorance, and for this reason many have objected to it; but this we cannot avoid. The word is, however, decidedly objectionable, when it is misapplied to express the idea of some particular medicine being the only one that can be used in a certain disorder. For this is an exaggeration of the truth that may lead to very serious error.
Before now proceeding to the proof of the minor propositions of Catalytics taken collectively, I must enumerate the chief remedies which I intend to include in the eight separate orders into which this division of blood-medicines has been divided.
Ord. 1. Antiphlogistics. Antimonials; Mercurials; Alkalies; Salines.
Ord. 2. Antisyphilitics. Mercurials; Preparations of Gold; Iodide of Potassium; Sarsaparilla (?).
Ord. 3. Antiscrofulitics. Iodine; Bromine; Chlorine; Iodides and Bromides; Potash.
Ord. 4. Antiarthritics. Colchicum; Nitro-hydrochloric Acid; Lemon-juice.
Ord. 5. Antiscorbutics. Citric Acid; Lemon-juice; Fresh Vegetables; Salts of Potash (?).
Ord. 6. Antiperiodics. Arsenious Acid; Arsenite of Potash; Alum; Chloride of Sodium.
Ord. 7. Anticonvulsives. Preparations of Arsenic, Silver, Zinc, Lead, and Copper.
Ord. 8. Antisquamics. Preparations of Arsenic; Sulphur; Pitch.
Under each head I have given the most important of those medicines which I conceive to act on the Catalytic principle. Other medicines may cure some of these disorders, or at least alleviate them; either by acting as Restoratives, as in the case of arthritic and of periodic disorders; or by influencing the nervous system, which plan may be effectual in some convulsive affections.
The prefix Anti- involves a principle. These medicines produce certain actions which are contrary to diseased actions, inasmuch as they neutralize them, and cannot subsist with them. It is granted that in some cases the actions may appear similar in some respects. But this merely shows that they move, as it were, in the same sphere, for else one of them could not meet the other. However the operation of a medicine may sometimes seem to resemble that of a disease, it is always in effect contrary to it. The similarity is of a kind which does not concern us. An acid and an alkali are so far similar, that they may both produce heat when mixed with water, and both prove corrosive and destructive to organized tissues; but they are practically contrary, and when brought together they neutralize each other. Let us now proceed to the minor propositions.
Catalytic medicines act in the blood, and their effect is permanent. This is simply to affirm that they belong to the class of Hæmatics, to which Restoratives also belong. Of all that I have named, there are not any, except Colchicum and Antimony, that possess in any degree the action of nerve-medicines—i.e. that exert a sudden and transient influence over the nervous system. I believe the sedative powers of these medicines to be quite distinct from their Catalytic influence. In the proof of the second minor proposition, I shall attempt to show that each of these remedies has a peculiar action of its own on the blood, even in health; which cannot be said of Restorative medicines. Of all these Catalytics two things are known. When they cure a disease, they do so definitely, so that it does not in general tend to return; and when they only alleviate it, the improvement effected is more or less permanent. In the second place, they are found to produce, after being long administered, a change for the worse in the blood, a diminution in the amount of Fibrine and of the red corpuscles. Thus they are blood-impoverishers, when given in excess. These considerations alone, when combined with the proof of absorption—i.e. that they all pass into the secretions, and may be detected there—are conclusive as to the fact of their being Hæmatic medicines. We pass on now to the third proposition, which consists in the statement of a property that is peculiar to Catalytic Hæmatics.
Each Catalytic tends of itself to work out a peculiar operation in the blood.
This peculiar process, established by their presence in the blood, forms part of the known history of each Catalytic medicine. It will suffice to demonstrate this if I condense into as few words as possible the facts that are known on this subject, with respect to each of the orders of this division of remedies.