G76 
RABIKS. 
of the power from a perpendicular line to the arm of the lever is 
attended with a corresponding decrease of force, and that the nearer 
the power approaches to the parallel line with the lever the weaker 
its effect, so much of the force being consumed in efforts either to 
drag the lever against the fulcrum or force it off, it will at once ap- 
pear evident at what a great disadvantage or sacrifice of power 
the muscles of the limbs, from their parallelism with the bones, 
are in general acting. This disadvantage, however, as I said be- 
fore, is greatly compensated for by the velocity acquired by the 
length of the resisting arm of the lever, and the comparative short- 
ness of that to which the power is affixed. Where power, how- 
ever, is wanted, as in the hock and fetlock joints of the hind ex- 
tremity, although celerity of motion is still preserved by the dis- 
tance at which the fulcrum is removed from the power, the requi- 
site force is gained by the proximity of the latter to the resistance. 
We now perceive the advantages derived from length of hock and 
length of elbow, and from broad or prominent fetlocks; we may 
also calculate to how much greater effect the muscles in the haunches 
and shoulders will act, where the bones are placed at right angles 
nearly to each other, and when, consequently, the power of the 
lever operates perpendicularly to its arm. In the case of the flexor 
muscles .of the arm playing over the head of the humerus, and that 
of the extensors of the thigh playing upon the patella, pulleys are 
established, which, though of a nature too simple in themselves 
to afford any advantage as pulleys, yet increase the power of the 
muscles attached to them by giving a more advantageous direction 
to the power over the resisting arm of the lever. These beautiful 
contrivances are likewise attended with the convenience of per- 
mitting the muscles from which the power originates being placed 
out of the direct line of action, in situations where they accord with 
the contour and proportions of the limb. 
RABIES. 
By Mr. James Turner, 311, Regent Street , London. 
Dear Sir,— -You having devoted a long and valuable life to the 
pathology of the inferior animals — the canine species especially, — 
and having succeeded (in my opinion at least) beyond any other 
man living in Europe in the enlightenment of the world as to 
the true nature of that terrific disease, termed Rabies, or Hydro- 
phobia, I am induced to trespass upon your valuable time, by 
addressing a few remarks within the compass of a short letter. 
