So that in Croup and Pneumonia, both rapid and fatal inflammations, Antimony is far preferable to Mercury. But in Pleurisy--where there is generally no immediate danger to be dreaded, but a subsequent effusion, Mercury is best, being in time to lessen or to prevent this result. From the action of both on the blood, and one on the nerves, these are very lowering remedies. In the employment of Antimony in fevers and inflammations, the production of nausea generally indicates that it has taken sufficient effect; but it may sometimes be better to give such a dose as shall cause vomiting, especially when a violent counter-irritant action is to be desired. The increase in the quantity of saliva, and slight soreness of the mouth, which result from its action, will show when the administration of a Mercurial has gone far enough. It is seldom advisable to cause copious salivation. Alkalies dissolve the Fibrine of the blood, and appear by this to lessen its deposition, and retard its formation. Thus, when given in large doses, they operate as Antiphlogistics. They have sometimes been employed with advantage in fevers of the acute or sthenic kind. Exerting an influence over the inflammatory process considered _per se_, Alkalies and Mercurials are more particularly efficacious in some special varieties of inflammation, because in such cases they further counteract the morbid agency by which the process is excited and kept up. In the Typhoid and Eruptive Fevers, when the blood is already sufficiently deteriorated, and it is not desirable that we should reduce the vital powers beyond a certain point, Salines, as Nitrate and Chlorate of Potash, supply us with a set of valuable and sufficiently mild Antiphlogistic agents. It seems that they both exercise a solvent power over Fibrine, and keep asunder the corpuscles which tend to adhere together in inflammatory blood. This latter action has been observed by Mr. Gulliver. Salts are excreted, and act on the skin, or the kidneys, or the bowels. They are not so potent as Alkalies; for salts pass out of the body as they went in; but Alkalies pass out into the secretions as salts, having first combined with acid in the system, so that they must leave behind them a certain excess of alkali in the blood, by which their action is continued for some time. (_Vide Alkalies; Prop. VIII.; Antimony and Mercury in Chap. IV._) ORD. II. ANTISYPHILITICS. These are medicines whose operation in the blood results in the counteraction or neutralization of the syphilitic poison. In primary forms of Syphilis, as the chancre, and early eruptions,--as syphilitic Lichen, Roseola and Lepra,--also in syphilitic Iritis, Mercury is the single and best remedy.