8 QUATERCENTENARY STUDIES IN PATHOLOGY 



Within 24 hours a copious growth had taken place in the tubes 

 prepared from the control blocks. On the other hand, all the tubes 

 containing the material which had been exposed to the vapour from 

 Lingner's apparatus remained sterile even after 7 days. 



. Experiment 2. 



The second experiment was carried out in a small ward of the 

 City Hospital, Aberdeen. It had 3 close-fitting two-sashed windows 

 and a stove, the outlet of which was closed by stuffing with paper. 

 The only other precaution taken was to suspend a wet sheet outside the 

 door to assist in preventing any fumes reaching the patients in the 

 adjoining wards. The size of the room was 16 ft. by 17 ft. by 10 ft., 

 giving a cubic capacity of 2,720 cubic feet, or just 80 feet under the 

 maximum allowed by Lingner for the adequate action of the apparatus. 

 The apparatus was placed in the middle of the floor. 



Technique. — Small pieces of glass, i in. long by \ in. broad, were 

 sterilized in the autoclave. The following micro-organisms were used : — 



1. actively sporing culture of Bacillus anthracis. 



2. 24 hours' agar culture of Staphylococcus pyogenes aureus. 



3. 24 hours' agar culture of Bacillus coli communis. 



4. 24 hours' agar culture of Bacillus typhosus. 



5. sputum containing the tubercle bacillus in large numbers. 



The cultures were made into emulsion with bouillon, and spread 

 on the sterile glass slips. The sputum was spread on an uncovered 

 Petri's capsule. All were allowed to dry in air. They were then 

 exposed in the following manner for three hours to the action of the 

 vapours from the Lingner apparatus : — 



1. One set of the four cultivations and one specimen of the sputum 



were placed on the floor, and protected from direct deposition 

 of the vapour by several loose layers of paper. 



2. One set of the cultivations alone were set on the mantelshelf above 



the stove. 



3. One set of cultivations and one of sputum were placed between 



two blankets — that is, having the thickness of two blankets 

 above and two below. 



(244) 



