670 MORTALITY AMONG THE EWES OF A FLOCK OF SHEEP. 
post-mortem examinations. The sheep did not die rapidly ; but 
one a week, and sometimes one a fortnight, or even three weeks. 
No previous illness whatever was manifested. They were always 
found dead in the attitude of sleep ; the countenance being tranquil 
and composed, not a blade of grass disturbed by struggling ; nor 
did any circumstance evidence that pain or suffering was en- 
dured. It was evident that the death was sudden. The general 
character of the post-mortem appearances was as follows : — 
All the abdominal viscera perfectly healthy ; only the liver 
in one or two cases being slightly congested, and, in a few, black 
and softened ; gall-bladder usually full ; but, as a general rule, 
the liver was healthy. Kidneys normal ; and in somes ewes near 
their time of lambing the uterus and contents bore no trace of dis- 
ease. The lungs, in every case but one that I examined, were 
quite sound ; but the cavity of the pericardium was invariably 
found filled with fluid, thickened, and coated upon both its interior 
and exterior surfaces with yellow transparent lymph. The heart 
was pale and softened, and also coated with lymph. The brain 
and spinal cord free from any traces of congestion or effusion. In 
the sheep whose lung was diseased there was considerable effusion 
into the cavity of the chest ; and the lung, where in contact with 
the pericardium, was quite consolidated. When I opened this 
sheep, about two hours after death (it was not cold), the peri- 
cardium was nearly bursting with fluid, and, as I have said, there 
was a considerable quantity of fluid in the chest. But it had not 
been exposed to the air one minute before all this fluid coagulated 
into pure transparent yellow lymph, just such as coated the heart 
and its covering. The cause of death was manifestly hydrops 
pericardii. So far so good. But what was the cause or causes in 
operation to produce this] Here was the puzzle. In the first 
place, all the sheep on the farm, save the ewes, were sound and 
healthy, and not one had died. No alteration, it seemed, had been 
made in their management differing from that of years gone by ; 
and yet the ewes, without any visible cause of difference, were 
constantly being found dead. No sheep on the adjoining farms 
were lost. And had it been an infectious disease, the rest of the 
flock would have suffered. That it was not hereditary or consti- 
tutional in the ewes was proved by the fact of Mr. F.’s purchasing 
some ewes from Dartmoor, and their becoming alike diseased. 
About 120 have thus died. Mr. Bickford, V.S., of Kingsbridge, 
was also consulted relative to the disease. I met him at the bar- 
ton on several occasions. He had not, certainly, the same chance 
to make post-mortem examinations that I had ; yet he was fully 
acquainted with every detail of interest. Despite all our cogita- 
tions, however, the mystery could not be solved or “ the plague 
