In a previous paper1 some experimental work was published, in which it was shown that irritation of the pleura by mechanical or chemical means would sometimes give rise to a reflex fall in blood pressure. It was shown also that this depressor reflex occurred more frequently when the irritant was applied to the inflamed pleura than to the normal pleura.
These results suggested the possibility of danger in the treatment of empyema by irrigation with antiseptic solutions. In order to determine how great this element of danger is, the following irrigation experiments were carried out on healthy dogs and on dogs with artificial empyema.
To produce empyema a few ounces of contaminated cotton-seed oil are injected into the pleural cavity of a dog. After forty to fifty hours the animal is languid and feverish. Examination of the thorax shows on the side injected an abundant seropurulent exudate and, as