Such is the difference between Restorative and Catalytic medicines. Although so far as this their action is sufficiently distinct, yet some care is required in separating the remedies in one division from those in the other. Sometimes both kinds are used in the same disorder. For whenever the action of a morbid poison causes any derangement in the proportion of the normal constituents of the blood, a Restorative may become of use to supply this defect. Thus a cancerous or scrofulous condition may cause a deficiency in the red colouring matter of the blood, which may be supplied by Iron. When, as in Gout and Rheumatism, there is an excess of acid in the system, partly due to an absence of that basic matter which should be present to neutralize it, this may be restored by an alkaline remedy. In both of these cases a Restorative may be used in a disease which depends on a morbid agency. But other remedies, Catalytic in their action, are of more direct use in such disorders. They counteract the original poison, and striking at the root of the evil, instead of correcting the consequences, they are more likely to eradicate the disease. Some medicines come under both heads, acting in different ways in different cases. Thus Potash may be a Restorative in Rheumatism, but a Catalytic in Scrofula. The operation of some particular agents is rather obscure. I shall have to show how it seems to me that the vegetable acids may act as Restoratives in fevers; and also to explain why, of those medicines which are used in Intermittents, I have placed Quina among Restoratives, and Arsenic with Catalytics. It may be remarked that the fact that Catalytic medicines produce of themselves distinct actions in the blood has proved a stumbling-block to the disciples of M. Hahnemann. For in some few cases their action may, to a certain extent, simulate the disease which they tend to cure, and has thus been confounded with it by this imaginative observer. This partial resemblance is probably due to the fact that both disease and remedy produce a series of changes in the same set of particles in the blood. If it were not so, the remedy could not meet the disease. It would be out of its province, as not acting at all in the same sphere. But that the actions are essentially different is sufficiently proved by the fact that they counteract each other. The remedy, moreover, is often of equal efficacy in other different disorders. It has been shown in Chapter II., that with regard to Eliminative medicines, the Hom[oe]opathic theory is founded on a misapprehension of facts.