The following methods of administering medicines in order of their
rapidity of absorption, beginning with the method by which absorption is
most rapid, and following with those by which absorption is less rapid
and finally least rapid: 1. Intravenous, by injection into veins. 2. By
inhalation (volatile drugs). 3. Subcutaneous, by injection into
subcutaneous tissue. 4. Intratracheal, by injection into the trachea (or
wind pipe). 5. Oral, by the mouth. 6. Rectal, by the rectum. 7.
Inunction, by the skin. 8. Intramammary injections.