apors; but such treatment is not so
common for cattle as for horses. In producing general anesthesia, or
insensibility to pain, the vapor of chloroform or ether is administered by
the nostrils. As a preliminary to this it is necessary to cast and confine
the animal. Great care is necessary to avoid complete stoppage of the heart
or breathing.

BY THE TRACHEA.--Medicines are injected into the trachea, or windpipe, in
the treatment of some forms of diseases of the lungs, and especially in
that form of bronchitis or pneumonia that is caused by lungworms. For this
injection a large hypodermic syringe, fitted with a very thick, strong
needle, is used. The needle is to be inserted about the middle of the neck
and between the cartilaginous rings of the trachea.

BY THE SKIN.--Although a number of drugs, notably mercury, are so readily
absorbed by the skin of cattle as to render poisoning easy, medicines are
not given in this way for their general or constitutional but only for
their local effect.

Diseases of the skin and superficial parasites are treated or destroyed by
applications in the forms of washes, ointments, dips, and powders.
Liniments and lotions are applied to the skin for the relief of some
near-lying part, such as a muscle, tendon, or joint. Blisters are applied
to the skin for the purpose of obtaining the effect of counterirritation
upon a neighboring region or organ. Cold water may be applied to the skin
to reduce the temperature and to diminish congestion or inflammation in a
superficial area or to reduce the temperature of the whole body. High fever
and heat strokes are treated in this way.

BY THE TISSUE BENEATH THE SKIN.--Hypodermic or subcutaneous injections are
often made for the purpose of introducing a drug, reagent, or vaccine
directly into the connecting tissue beneath the skin. Introduced in this
way, the substance is quickly absorbed, none of it is lost, and its whole
effect is obtained, often within a few minutes.

There are numerous precautions necessary in making a subcutaneous
injection, most of which have to do with cleansing and sterilization. It is
also important to select a proper site for the injection, so that blood
vessels, joints, and superficial nerves, organs, or cavities may all be
avoided. With due regard for the necessary precautions, there is
practically no danger in such an injection, but it should be attempted only
by those who are able to carry it through in a surgically cl