AN INEXPENSIVE HOOD FOR INDIVIDUAL STUDENTS I. LIN C
Fukien Christian University, Foochow, China
IN CONCENTRATING sulfuric acid and removing nitric and hydrochloric acid in qualitative analysis, and in destroying the organic matter in the Kjeldahl digestion, the acid fumes produced necessitate the use of a hood. To use a hood which is remote from the working table is quite inconvenient as carrying apparatus and idly watching the evaporation proceed wastes much time. Also the running of a big motor in the hood for the sake of one person is not economical. It will be a simple matter to invert on the gas outlet an ordinary funnel connected to water pump. The gas produced dissolves in the running water. If the duration is rather long or if the fumes attack the rubber tubing, a wash bottle containing sodium hydroxide must be inserted. In case the condensed liquid may drip back into the evaporator with the danger of carrying with i t undesirable matter from the rubber, the stem
of the funnel must be bent and the connection made as shown in the accompanying figure.
