ally as a deodorizer during a set of experiments, and always as a disinfectant at the end of the hour. Its own odor is easily washed away. As it takes some time for a porcelain cylinder to become thoroughly impregnated with an odorous solution, it is convenient to have test-tubes with tightly fitting corks, in which a number of cylinders may be put to soak at the same time. Unless they can be keptin a dark cupboard, it is well to wrap up these tubes in several plies of black calico. Bottles of yellow glass, such as perfumers recommend for the safe keeping of heliotropine, might well be used for all the solutions, but if they are not available, the ordinary bottles of colorless glass can be wrapped up in black cotton cloth. The less woolen cloth about the room, the better. We keep our solid cylinders in “self-sealing” preserve jars. When the cylinder with its fluid-mantle in place is not in use, the bore should be corked to keep the inner surface from drying of. It may, indeed, be filled with the solution and corked when it is put away for some time. In this case, all drops of liquid must be wiped out with absorbent cotton before the experiments begin. If it seems likely that much odorous substance has condensed on the inner surface, the whole bit of apparatus, glass shell and all, may be immersed in water. The bore should then be filled for a few hours with the odorous liquid.
The walls of the room in which our experiments were made are covered with oiled paper, and the floor is covered with oil-cloth which has a coating of shellac. The room has at present this defect, that when the wind blows in certain directions, it is impossible to create through it a draft of air which does not pass first through a hall frequented by students and therefore dusty, and by no means free from odor. When the standard olfactometer was used, the subject sat between the observer and the window, and at right angles to the observer, so that the light shone through the graduated inhaling-tube. When the fluid-mantle olfactometer was used, subject and observer sat at right angles to each other at the end of a low table.
Chapter III. Results.
Section 1. The Several Subjects and their Stimulus-Liming.
Individual variations in the sense of smell are so great that it is necessary to preface a chapter on experimental results with an account of the subjects. The following notes upon our subjects in alphabetical order are thrown into “noun-form” for the sake of brevity.
Be. (Dr. I. M. Bentley), a trained subject.
Organ impaired by acute catarrhal troubles and easily exhausted.
Breathing spols always blurred and ragged at the division lines,—indicating a catarrhal condition of the membranes,—and never quite
symmetrical.
rλ usually determined with one inspiration ; Δr determined with from 2 to 4 inspirations.
Movements of cylinder long and slow, but few.
Position indicative of strain.
Bi. (Miss E. M. Bickham), a wholly untrained subject. General physical condition neurasthenic.
Organ twice operated on (in ’95 and ’96) for hypertrophy of the
