of the articulations, a common swelling seems to identify them with the neighbouring cellular texture. They have not like the other glands, affections distinct from those of this texture, no doubt because they have not a peculiar vitality, because being mere elongations of the neighbouring cellular texture, they partake of its nature and properties, and ought consequently to partake of all its conditions, as it in its turn ought immediately to receive the influence of their affections. The considerations which I have just offered successively form, I think, sufficient data to resolve the problem proposed above, by establishing as an incontestable proposition, that the synovia is not transmitted by secretion to the articular surfaces. Let us examine the second mode of transmission stated by authors. _Is the synovia transmitted by transudation to the articular surfaces?_ It was an opinion anciently received, that the marrow of the long bones oozes through the pores of their extremities and through those of the cartilages which terminate them, to lubricate the articular surfaces. Havers renewed this idea forgotten at the time he wrote, united this source of the synovia to that which had placed it in the glands, and thus formed of this fluid a mixture composed of two fluids differently transmitted to the articulation. The most of those who succeeded him partook of his opinion upon this point. Those even, such as Desault, who rejected the existence of the articular glands and the secretion of synovia, admitted the transudation of it founded upon the following observations. 1st. A long bone, stripped of its soft parts and exposed to the air, allows a fatty oozing to pass through the pores of its cartilages which does not cease till the medullary juice is completely exhausted. 2d. The mechanical compression of the cartilaginous extremity of a long bone produces for a moment the same effect. Are these facts, which are evident in the dead bone, also real in the living one? Different considerations, which I will now state, induce one to believe the contrary.