If the injection is not pushed very far, it is confined to the capillary system; but if it succeeds, it pours from all parts upon the surface, where exhalation takes place in the ordinary state. This dew mechanically produced, evidently resembles that which the tonic force of the parts occasions during life; for, as I have said, if it was a transudation, there would be extravasation in the neighbouring textures, whereas nothing is filled from the syringe which propels the injection to the exhalants that pour it out, except the arteries, the capillaries and these exhalants. Besides, when there is active hemorrhage, the capillaries from which arise the exhalants that pour out the blood, are evidently more full of fluid than ordinary, as I have already remarked. From these considerations and many others that will be explained hereafter in this system, I think that we may consider the exhalants as arising from the capillary system, by means of which they are continued with the arteries, which bring them the materials of exhalation. But to say what is the length of these vessels, what their form, what course they run, is evidently impossible; it is here that the imaginary descriptions begin. We distinguish with difficulty their orifices. We see upon the skin many little pores that evidently form communications from within to without; but these pores transmit not only the exhalants, but also the absorbents, the hair, &c. as we shall see in the dermoid system. 1st. The existence of the exhalants; 2d, their origin in the capillary system of the part where they are found; 3d, their termination upon different surfaces, are upon the whole all that is accurately known. The mode of origin undoubtedly varies, but we do not know how it takes place. The exhalants are continued with their capillary net-work, in such a manner that we cannot say precisely where one finishes and the others begin. Hence why often in this work, in speaking of these small tubes, I suppose them to come immediately from the arteries, and forming the capillaries by their interlacing; this is evidently sufficient to understand what will be said hereafter. II. _Division of the Exhalants._ There are three classes of exhalants which I distinguish by the fluids or the substances they furnish. The first class contains those that throw out the fluids not destined to enter the economy again; such are, 1st, the cutaneous exhalants that pour out the sweat; 2d, the mucous exhalants that furnish a part of the pulmonary perspiration, the greatest part being formed, as I shall say, by the dissolution of the mucous fluids of respiration, which yield perhaps the gastric, intestinal juices, &c.