Note 628 — BOOK I.—OF THE EPIDEMICS.

Galen thus explains the origin of the ophthalmies. He says, the constitution of the air being not only cold and humid, but attended also with hurricanes. The eyes were thus injured, and consequently were the first part of the body to show symptoms of disease. The dysenteric and other alvine complaints which followed, he ascribes to the constriction of the skin induced by the cold, and to the humoursæ of the system aggravated and increased by the humid state of the season. These humours being thus shut up by the occlusion of the pores of the skin, part of them were determined to the intestines, occasioning diarrhœa, tenesmus, dysentery, etc.; some to the bladder, inducing strangury; and some to the mouth of the stomach, occasioning vomiting.