pitting. The malady is so grave
that it should be intrusted to the care of the family physician.

VARIOLOID. (MODIFIED SMALL-POX.)

Varioloid is a modified form of small-pox. There is less constitutional
disturbance, and very little or no pitting of the skin. Varioloid
generally occurs in persons who have not been fully protected by
vaccination. A person suffering from this modification of the disease
may, by contagion, communicate to another genuine small-pox. The
_treatment_ is the same as that recommended in variola.

VACCINIA. (COW-POX.)

The important discovery of vaccination is due to Dr. Jenner, who
ascertained that when the cow was affected by this disease and it was
then communicated to man, the affection was rendered very mild and
devoid of danger, and at the same time it proved a very complete
protection against small-pox. Like most other valuable discoveries
introduced to the world, it encountered bitter prejudice and the most
unfair opposition. Now its inestimable value is generally known and
admitted.

In a few cases, in which the quality of the vaccine virus was
deteriorated, its effect is only to slightly-modify small-pox, and then
the disease resembles that caused by inoculation. The operation of
infecting the blood with the _kine virus_ is called _vaccination_. All
that we know is that when the cow becomes affected with this disease,
and it is then transferred to man, it loses its severity and serves as a
protection against small-pox. In a great majority of cases this
protection is absolute, and only in a very few does it leave the subject
susceptible to small-pox, materially modified. The protection it affords
against small-pox is found to diminish after the lapse of an indefinite
number of years, and hence it is important to be re-vaccinated once or
twice, for instance, after an interval of five years. Between the second
and third months of infancy is the best period for vaccination, and the
place usually selected is the middle of the arm above the elbow-joint.

CHICKEN-POX. (VARICELLA.)

Chicken-pox is an eruptive disease, which affects children, and
occasionally adults. It is attended with only slight constitutional
disturbance, and is, therefore, neither a distressing nor dangerous
affection. The eruption first appears on the body, afterwards on the
neck, the scalp, and lastly on the face. It appears on the second or
third day after the attack, and is succeeded by vesicles con