REMOVAL OP A LARGE MALIGNANT TUMOUR. G39 
jugular veins. I therefore thought it most likely that an 
operation would be attended with much danger ; but, not- 
withstanding my opinion, he was determined to have it done. 
On the 2 1st of June, therefore, I had the mare cast, and 
being kindly assisted by Mr. Sharman, M.R.C.Y.S., 1 dis- 
sected out no less than 7 lbs. of the tumour. The hemorrhage 
was very great, and the mass, when cut into, was found to be 
of a scirrhous nature, without sensibility, but supplied with 
numerous blood-vessels ; and about the centre was a small 
abscess, containing a little greyish matter. I stopped the 
bleeding, and left her almost to nature for the next and two 
or three following days, as I thought all was going on well, 
merely dressing the parts with mild caustics, and anticipated 
a speedy termination to the case. The remaining portion of 
the tumour protruded itself much below the surrounding 
muscles, from which it was easily separated, and 1 could get 
my hand quite round it, as deep as its roots, and I thought I 
should be able to pluck it out by the roots, but determined 
not to do so for two or three more days. But in this time it 
had got so large that I found my hopes of plucking it out 
were at an end. I therefore excised it again, taking off 4| lbs. 
more of it as the mare stood ; for I might here observe, that I 
did not cast her any more, she standing well to have it either 
dressed or cut. Much bleeding took place from several 
arteries, and mostly from the larger one, to which 1 applied 
the cautery. The substance being of a tough and elastic 
nature, I soon succeeded in plugging them up. In three 
days more the tumour was again as large as ever. I now cut 
off 4 lb. more, and to the bleeding vessels applied the cautery, 
as before. I now began to think that something else must 
be done. I therefore determined on trying to destroy the 
organized mass. To effect this, I made incisions with a scapel, 
transversely round the tumour, and as near to its base as pos- 
sible, which now covered a space as large round as half a peck 
measure; these I filled with cut tow, on which was sprinkled 
arsenious acid. This I repeated three times, introducing 
half an ounce of the acid each time, but less and less quan- 
tities afterwards, as I thought the case required. I soon 
found that its structure was destroyed, and when cut into it 
had a dark grey aspect. No bleeding took place, but instead, 
a watery fluid exuded ; and I dissected out at different times 
20 lb. of the disorganized mass. About this time the animal 
showed symptoms of the acid having entered the system, as 
she was a little off her feed. A few days after, as I was 
cutting away some of the dead parts from between the left 
side of the trachea and jugular vein, I accidentally divided a 
