416 OPEN SYNOVIAL CAVITIES. 
Should the horse be nervous, it is desirable to blindfold the animal 
and order the groom to hold up the sound leg; the creature can then 
only rear. When thus disabled, that movement is rendered difficult, and 
it is proportionably slow. The operation, if properly performed, should 
be over before action can be prepared for; and by the knife a consider- 
able incision is made in the bottom of the sac, through which all grit or 
dirt can, with the pus, readily pass. 
The examination concludes with a second resort to the probe. The 
instrument is in surgery of great use; but as it is commonly employed, 
reason may donbt whether injured life has been much benefited by its 
invention. It generally is raked and poked about as though the person 
holding it was determined, at all hazards, to ascertain the length, 
breadth, and every irregularity of the wound he is asked to cure; much 
harm is thereby done. Delicate attachments which, if not interfered 
with, might induce speedy reunion, are thus broken down, and the injury 
aggravated; while the operator thinks he ought to know all about the 
lesion he is to treat, and supposes that he can possibly do no harm with 
an instrument which the best schools order to be employed. , 
A good surgeon has no curiosity to gratify; all he desires to know is 
so much as will enable him to benefit the patient 
placed under his care. Therefore never abuse the 
probe in cases of open synovial cavities. Imagine 
the distance the bones are from the surface; and, 
if the probe can enter a very little beyond that 
distance, such a fact demonstrates the cavity to be 
exposed. When a horse is before you with syno- 
via running from a wound upon the knee, have the 
leg slightly flexed; look for the most free space, 
vrourva AN ovey gorxn, 2nd into that insert the probe. The bones of the 
knee-joint are directly under the skin; and, when 
no opposition is encountered for three-quarters of an inch, be sure the 
joint is exposed, 
Most of the cases narrated as opened joints were simply punctures 
into synovial sheaths; as such, they were sufficiently serious, but not of 
so important a character as is assumed for them. Synovia is placed 
between the ends of bones, its use being to prevent the friction which 
otherwise would be occasioned by the movement of one hard body upon 
another. Being confined in a circumscribed sac and incapable of much 
compression, the liquid performs all the uses which could appertain to 
the most solid substance. When the fluid—which, from its thick appear- 
ance and unctuous feel, was formerly termed “joint oil”—has escaped, 
the bones grate against each other, inflammation ensues, all neighbor- 
