This is a contribution on pneumonia by the professor of medicine at McGill University. It is, as have been previous volumes of this series, succinct, well written, handsomely printed and quite up to date. The views of Dr. Howard as to serum treatment are of especial interest. He reviews fully the work of Cole, of Kyes, of Huntoon and of Felton. He believes that unquestionably the serum exerts an influence on the disease. The case for the Kyes method is not considered as established. The value of the Huntoon preparation is called to question because of the severe thermal reactions; there seems to be some evidence of benefit in some cases. The author is most enthusiastic about the Felton preparation and urges its use in pneumonia without exception as to type, provided the patient is seen within the first three days of the disease.