WATER IN THE HEAD. 205 



season, but more on the health and strength of the animal. It may 

 be prevented by good and upland pasture ; and is most common in 

 low and marshy ground. It is not contagious, nor does it seem to be 

 hereditary. Having once attacked the animal, and gradual loss of 

 flesh having commenced, the case is hopeless. 



All medicine will be thrown away in such a case. It is the conse- 

 quence of pressure on the brain by a strange, bladder-like-formed 

 animal ; and it would be more for the advantage of the owner to de- 

 stroy the sheep, however out of condition it may be, than to com- 

 mence any desperate and fruitless course of medicine. 



Various methods have been tried in order to break this bladder, 

 such as hunting the sheep with dogs, and frightening him half to 

 death, throwing him into a gravel-pit, and various other absurd as 

 well as brutal methods. They who pursued this course much oftener 

 succeeded in breaking the animal's neck than rupturing the bladder. 

 At length some persons bethought them of getting at, and puncturing 

 or removing, this bladder by some operation. They thrust iron wires 

 or skewers up the nostril, and into the brain, and sometimes succeed- 

 ed in effecting their purpose. If they hit upon the nuisance, and 

 pierced its envelope or skin, they were made aware of it by a greater 

 or smaller quantity of water flowing from the nostril, and they could 

 always tell on which side the hydatid lay, by the sheep inclining his 

 head that way. They could also sometimes tell the precise situation 

 of the bladder ; for after being a long time inclosed between the skull 

 and the brain, and pressed upon by both, and pressing upon both of 

 them in turn, not only in consequence of that pressure was a portion 

 of the brain below destroyed and absorbed, but even the bone above 

 was softened, nothing but a yielding membrane sometimes remaining 

 over a particular spot. Some surgeons suggested that this membrane 

 should be punctured, and it was done so with the lancet, or, oftener, 

 by a heated sharp-pointed wire, and thus the creature beneath was 

 wounded and destroyed. Others improved upon this method of 

 operating. A surgeon's trephine was used, and a circular piece of 

 the skull taken out at the place where it was softened, and thus the 

 hydatid was bodily removed ; and when this was carefully done, and 

 the bladder was not broken, the hydatid, by slight but sufficiently 

 distinct motion, when put into warm water, showed that it was alive. 



Both these operations occasionally succeeded, but the instances of 

 failure were so numerous, that the farmer's interest still required that 

 he should kill every sheep, unless a favourite, or very valuable one, 

 as soon as he was evidently sturdied, and before he had wasted and 

 become unlit for the market. 



There may, however, be some prevention, although no cure; and 

 that prevention consists in good, and sufficient, and upland pasture : 

 yet in some untoward seasons even this will not avail with unhealthy 

 and weakly animals. Habitual shelter from the sleet and snow of 

 winter is another and very important means of prevention. The un- 

 feeling abandonment of the sheep to all the inclemency of the coldest 

 18 



