k also manifested itself in our other herd that summer;
first one of our Black Dutch belted heifers, and then several others
took to gnawing the bark from young trees in their pasture and along the
lanes to the barn. Before we noticed what they were doing, the bark from
twenty or more young maples, elms and other trees had been gnawed and
stripped off as high as the heifers could reach. It was not from lack of
food; there was grass enough in the pasture, and provender and hay at
the barn; but an abnormal appetite had beset them; they would even pull
off the tough bark of cedars, in the swamp by the brook, and stand for
hours, trying to masticate long, stringy strips of it.

In consequence, probably, of eating so much indigestible bark, first
one, then another, "lost her cud," that is, was unable to raise her food
for rumination at night; and as cattle must ruminate, we soon had
several sick animals to care for.

In such cases, if the animal can only be started chewing an artificially
prepared cud she will often, on swallowing it, "raise" again; and
rumination, thus started, will proceed once more, and the congestion be
relieved.

For a week or more we were kept busy, night and morning, furnishing the
bark-eaters with cuds, prepared from the macerated inner bark of sweet
elder, impregnated with rennet. These had to be put in the mouths of the
cows by main strength, and held there till from force of habit the
animal began chewing, swallowing and "raising" again.

What was stranger, this unnatural appetite for gnawing bark was not
confined wholly to cows that fall; the shoats out in the orchard took to
gnawing apple-trees, and spoiled several valuable Sweetings and
Gravensteins before the damage was discovered. It was an "off year."
Every living thing seemed to require a tonic.

The bitter milk proved the most difficult problem. No bitter weed or
foul grass grew in the pasture. The herd had grazed there for years;
nothing of the sort had been noticed before.

The village apothecary, who styled himself a chemist, was asked to give
an opinion on a specimen of the cream; but he failed to throw much light
on the subject. "There seems to be tannic acid in this milk," he said.

At about that time uncle Solon Chase came along one afternoon, and gave
one of his harangues at our schoolhouse. I well remember the old fellow
and his high-pitched voice. Addison, I recall, refused to go to hear
him; but Willis Murch and I went. W