306 DISEASES OF THE CELLULAR MEMBRANE. 



The ordinary situation of these swellings is upon the 

 outer side of the thigh, in front of the stifle : likewise upon 

 the breast, the shoulder, and the arm. Though circum- 

 scribed, they are occasionally of considerable volume. Their 

 shape is ovoid, flattened upon the surface. They have a 

 soft, fluctuating feel; and, when punctured, emit a jet of 

 straw-coloured fluid, very like the serum of the blood. 



The Causes producing these swellings are not obvious to 

 me at present. C. Percivall told me they arose from blows,^ 

 or other external injuries. 



I feel convinced serous abscess often has its origin in 

 external injury. A young troop-mare received a kick upon 

 her stifle. Next morning I saw the animal : there was 

 the mark of the injury plain enough, the place being bare 

 and abraded ; it was also accompanied with a swelling all 

 around the place, and was evidently nothing more than a 

 serous abscess : it felt precisely like a bag half filled with 

 water. This is, then, certainly, one kind of serous abscess, 

 which follows external injury; but is there not another kind 

 — a sort that arises spontaneously, or without any traceable 

 injury whatever? 



Treatment. — It is time lost to attempt dispersing these 

 tumours. The most summary mode of getting rid of them 

 is to plunge a lancet in and evacuate the contents. Were 

 we, however, to do nothing beyond this, in a day or two the 

 tumour would become as large as ever. Evacuate it a 

 second time, and the fluid will still re-collect. In fine, to 

 make a cure, we must follow up the evacuation by throwing 



' May, 1842. — I have now under my care a remarkable proof of this origin. 

 A troop-mare slipped down upon her side in the stable, at the Horse Guards, 

 and fell against her stirrup. The consequence was a tumour upon her ninth 

 and tenth ribs, which was fluctuating, and evidently full of fluid. Some days 

 afterwards it had grown as large as an orange, and, being opened, about half a 

 pint of yellow watery (serous) fluid escaped. 



February, 1843. — A mare (C 31), three years old, was brought to me with a 

 large serous abscess upon the stifle, rather more inclined to the inner than to the 

 outer side. The fluid evacuated was of the common character, showing albu- 

 minous deposit on the addition of a solution of corrosive sublimate, and mea- 

 sured twentv ounces. 



