The effect of the respiration of putrid gases upon the growth of guinea pigs

Three years ago Mr. G. T. Palmer and the senior author reported here a series of experiments on human subjects conducted by the New York State Commission on Ventilation which indicated that “there are substances present in the air of an unventilated occupied room (even when its temperature and humidity are controlled) which in some way, and without producing conscious discomfort or detectable physiological symptoms, diminish the appetite for food. 2

A natural assumption would be that odoriferous materials contributed to the stale air by the bodies and clothing of the occupants might produce such an effect upon appetite; and the present study is an attempt to detect a possibly analogous effect of putrid odors of a more intense kind upon the growth of guinea pigs.

A galvanized iron box 4 feet wide, 2 feet deep and 3 feet high was constructed and divided into two equal vertical compartments, each holding two standard animal cages and each provided with a separate glass door. Fresh air to the amount of 1.5 cubic feet per minute for each compartment (amounting to 4 liters per minute per animal) was supplied to the box by a small centrifugal fan, the supply to each section of the box being carefully regulated by dampers. On the course of the branch duct leading from the fan to one section was inserted a chamber in which was placed a pan of fresh moist human or dog feces, so as to produce a strong fecal odor in that section of the box.

Fifteen different series of tests were conducted with this apparatus during the years 1916, 1917 and 1918, 261 animals in all being used. Young guinea pigs were selected, usually weighing between 150 and 300 grams, and they were kept under the experimental conditions for from 4 to 24 days, being weighed each day.