[ 5 '4 j 
VI. Of the Structure and Difeafes of Articu- 
lating Cartilages, by William Hunter, Sur- 
geon • 
Read June 2. HpHE Fabric of the Joints in the 
743 JL Human Body is a Subjcd fo much 
the more entertaining, as it muft ftrike every one that 
conlldcrs it attentively with an Idea of fine mecha- 
nical Compofition. YVhere-ever the Motion of one 
Bone upon another is requifite, there we find an ex- 
cellent Apparatus for rendering that Motion fafe and 
free: We fee, for Infiance, the Extremity of one 
Bone moulded into an orbicular Cavity, to receive 
the Head of another, in order to afford it an extenfive 
Play. Both are covered with a fmooth elafiic Cruft, 
to prevent mutual Abrafionj connected with ftrong 
Ligaments, to prevent Diflocation ; and inclofed in a 
Bag that contains a proper Fluid depofited there, for 
lubricating the Two contiguous Surfaces. So much 
in general. 
But if Curiofity lead us a Step further, to examine 
the Peculiarities of each Articulation, we meet with 
a Variety of Compofition calculated to all the Varie- 
ties of Motion requifite in the Human Body. Is the 
Motion to be free and extenfive in one Place? There 
we find the whole Apparatus contrived accordingly. 
Ought it to be more confined in another? Here we 
find it happily limited. In fhort, as Nature’s Inten- 
tions arc various, her Workmanfifip is varied accord- 
ingly. 
Thefc 
