It must be observed, that, as these metals have some affinity with the Regulus of Antimony, the Regulus will be joined in the operation by some of the metal employed as a _Precipitant_, (so those substances are called which serve as the means of separating two bodies from each other); and therefore the Regulus procured in this manner will not be absolutely pure: on this account care is taken to distinguish each by adding the name of the metal employed in its precipitation; and thence come these titles, _Martial Regulus of Antimony_, or only _Martial Regulus_, _Regulus Veneris_; and so of the rest. Antimony is employed with advantage to separate Gold from all the other metals with which it may be alloyed. It has been shewn, that all the metals have a greater affinity than the reguline part of Antimony with sulphur, Gold only excepted; which is incapable of contracting any union therewith: and therefore, if a mass compounded of Gold and several other metals be melted with Antimony, every thing in that mass which is not Gold will unite with the sulphur of the Antimony. This union occasions two separations, to wit, that of the sulphur of the Antimony from its reguline part, and that of the Gold from the metals with which it was adulterated; and from the whole two new compounds arise; namely, a combination of the metals with the sulphur, which being lightest rises to the surface in fusion; and a metalline mass, formed of the Gold and the reguline part of the Antimony united together, which being much the heaviest sinks to the bottom. There is no difficulty in parting the Gold from the Regulus of Antimony with which it is alloyed: for the metalline mass needs only be exposed to a degree of fire capable of dissipating into vapours all the Semi-metal it contains; which being very volatile, the operation is much easier, and more expeditiously finished, than if the metals with which the Gold was debased were to be vitrified on the cupel; without taking into the account, that, if Silver were one of them, recourse must needs be had to the process of quartation after that of the cupel. If equal parts of nitre and Antimony be mixed together, and the mixture exposed to the action of fire, a violent detonation ensues; the nitre deflagrating consumes the sulphur of the Antimony, and even a part of its phlogiston. After the detonation there remains a greyish matter which contains fixed nitre, vitriolated tartar, and the reguline part of the Antimony in some measure deprived of its phlogiston, and half vitrified by the action of the fire, which is considerably increased by the deflagration. This matter is called _Liver of Antimony_. If, instead of equal parts of nitre and Antimony, two parts of the former be used to one of the latter, then the reguline part loses much more of its phlogiston, and remains in the form of a yellowish powder.