212 
SALIVARY CALCULI IN THE HORSE. 
with the lowermost one; here I noticed a distinct cavity, 
capable of holding quite an ounce of matter, and having walls 
moderately firm and smooth. The blood-vessels of the pia 
mater of the brain were filled with stagnant blood, and the 
plexus choroides of the fourth ventricle was so much thick¬ 
ened from interstitial deposition as to suggest the idea that 
the undue pressure it would impart to the medulla oblongata 
might influence voluntary motion, and which, to a certain 
extent, would account for the horse^s inability to rise when 
in a recumbent position. 
SALIVARY CALCULI IN THE HORSE. 
By G. A. Drewe, M.R.C.V.S., Abingdon. 
On the 26th of last month I left with Professor Varnell 
at the Royal Veterinary College two salivary calculi, which 
I had taken from the parotid duct of an aged gra 3 ^-mare, the 
property of a small farmer of the name of Wallace, residing 
at Oare, near this town. 
The animal was brouglit to me on the 11th of December 
on account of a difficulty in mastication, and on examination 
I detected the presence of the above-mentioned calculi. An 
effort was made to force them from the termination of the 
duct, but finding that course not practicable, 1 cut down on 
the enlarged duct (making an incision about an inch and a 
half in length), and very easily extracted them. A couple of 
sutures were inserted, and some stjqitic powder sent to dress 
the wound with. There was a considerable escape of saliva 
for the next week; but, nevertheless, the healing process 
went on satisfactorily. On the 22nd the actual cautery had, 
however, to be applied. 
I called on January 9th, in company with my friend Mr. 
Naden, of the Royal Artillery, and found the wound was 
perfectly healed, and the mare much improved in condition. 
ANALYSIS OF THE SALIVARY CALCULUS BY PROF. TUSON. 
The calculus submitted to examination was one of the 
two removed from the salivaiw duct. Both calculi were 
more or less oval in shape, about an inch and a half 
