Entomological News 1933 Vol 44 Classic Reprint

Excerpt from Entomological News, 1933, Vol. 44 A bunsen suction pump was used to draw the air through the Olfactometer. It was connected with the small vertical out let Ou the stern. The air for one Of the intake tubes on the arms of the Y was bubbled through a flask of water, then led through the Odoriferous substance to be tested. The air for the other intake tube was only bubbled through the water. The intake tubes Of the Olfactometer were plugged with cotton, which served both as a filter against droplets or dust of the substance being tested and as a barrier against the occasional earwig which might attempt to ascend the tube. The outlet tube was similarly plugged. Stoppers were put in the ends of the Y when the apparatus was being used. In a preliminary experiment, when no Odoriferous substances were being tested, earwigs had shown a tendency to go into the arm Of the Olfactometer in which air was moving the more rapidly. Therefore, in the experiment proper, every effort was made to equalize the currents of air in the two intake arms. All resistances to the air currents, such as the bends in the tubing and the depth Of water in the flasks, on the two sides were balanced as closely as possible, in setting up the apparatus. Then pinch-cocks were used to help in the equalization. To further approach equality between the two currents, and to ensure a nearly constant rate of flow, the currents were each run through five feet of glass tubing, one millimeter inside diameter. The rate at which air was passing through each side Of the intake systems was judged by the number of bubbles per minute in the flask Of water on each side. A liter of air was drawn through the system in two minutes. In order to eliminate the influence Of bias between the arms on comparative readings between the two intake systems, the latter were changed over from one arm to the other after every two readings. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.