﻿ORGANIC MATTER IN AIR. 



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Fig. 2. — Apparatus used in Method II. It consists of : a — a small globe-shaped 

 glass tube containing the glass-wool absorbent for the dust in the air ; & — a small 

 Erlenmeyer flask containing the acidulated permanganate solution to absorb the 

 gaseous organic matter ; c — a graduated flask of eight litres capacity, which 

 serves as an aspirator ; and d — another eight-litre flask into which the water 

 drains from the aspirator. 



Fig. 3. — Apparatus used with Method III. It consists of : a — a small glass tube, 

 twenty centimetres in length, consisting of a narrow portion four centimetres 

 long and three millimetres in its internal diameter, and a dilated portion sixteen 

 centimetres long and twelve millimetres in its internal diameter. This tube con- 

 tains the granular pumice-stone which serves as the absorbent material in this 

 method ; b — is the gas-meter ; and c — a Chapman water pump. 



