4ftt PHILOSOPHICAL TRANSACTIONS. [aNNO IGQI. 



In the 4th discourse is an account of a particular sort of glands, which he 

 calls the mucilaginous glands seated in the joints. These are of two sorts ; 

 some are small, and in a manner miliary glands, being glandules placed all upon 

 the same surface of the membrane, which lies over the articulations. The 

 other sort are conglomerate, or many glandules collected, and planted one 

 upon another, so as to make a bulk, and considerable glands. In some of the 

 joints there are several of them, and others but a single gland. They have 

 their blood vessels, as other glands, but their veins have a particular flexure in 

 their course, for retarding the return of the blood from the glands, that the mu- 

 cilaginous liquor, which is not separated with the greatest expedition, mayh ave 

 time to penetrate the secretory pores of the glandules. The large mucilaginous 

 glands are variously seated, some in a sinus formed in the joint, others stand 

 near or over against the interstice between the articulated bones : but in ge- 

 neral they are so placed as to be squeezed gently, and lightly pressed in the 

 inflexion or extension of the joint, so as to separate a quantity of mucilage 

 proportionate to the motion of the part, and the present occasion, and yet 

 without any injury. Here is also some description of the commom membrane 

 of the muscles ; how it is every where set thick with the small mucilaginous 

 glands ; and about some joints which are often moved, and where the tendons 

 run backward and forward more considerably, it has some larger or conglome- 

 rate glands. 



The design of all these glands is to separate a mucilaginous kind of liquor, 

 that serves principally to lubricate the joints, to make them so slippery as to 

 be moved with the greatest facility imaginable. It serves likewise to preserve 

 the ends of the articulated bones from attrition, and an immoderate incales- 

 cence. But all these things it performs in conjunction with the medullary oil. 

 Of which two ingredients is made a composition admirably fitted for those ends : 

 for the mucilage adds to the lubricity of the oil, and the oil preserves the muci- 

 lage from growing too thick and viscous. 



Then follows an account of some experiments made with the mucilage ; most 

 of which come to this, that all acids coagulate it, as all austeres, and austere 

 acids ; but with this difference, that the coagulum or curd made with acids 

 only is tenderer than that which is produced by an austere only, or an austere 

 acid. These experiments being made and described in order to explain the 

 nature and causes of a rheumatism, and the gout, these distempers are next 

 treated of. 



The generation of the tophaceous matter, in the nodose gout, is accounted 

 for, from the experiments made with acid-austere liquors mixed with the muci- 

 lage ; so that where the gout is nodose, the mucilage is first coagulated by some 



