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.