174 LECTURES. 



each room. Illustrations were taken from schools in Westminster 

 and other places, and cases cited where excessive crowding had led 

 to six times the number originally intended being accommodated in 

 particular schools. In this country his own observation, as well as 

 the concurring testimony of different reports he had seen, led him to 

 the conviction that much was still to be done before the ventilation of 

 schools could be considered on a proper footing. The supply was, in 

 general, too small, the means of discharge not sufficiently powerful, 

 and the ascent of the warm entering air so rapid, that much of it escaped 

 by the ceiling without doing any good, unless made to descend to the 

 floor by opening the discharge there, and closing the aperture above, 

 when the products of respiration descended along with it. The diffu- 

 sion of heat, also, was rarely general and equal, and hence it was 

 often impossible to give sufficient fresh air without opening the win- 

 dows at times when the state of the external atmosphere indicated 

 that they ought, if possible, to be closed. In some more recent cases 

 the diffusion of heat had been very much extended and improved, but 

 not the ingress of air. 



In hospitals much required to be done, more especially where con- 

 tagious diseases were treated ; he considered that great improvements 

 might be made in such cases by causing all the expired air and ex- 

 halations to pass directly from each individual patient to a ventilating 

 flue, where, by the action of heat, every noxious emanation could be 

 entirely destroyed, so as equally to save life within doors and relieve 

 apprehension without. In this country, at the New York Hospi- 

 tal, he had seen arrangements that were in advance of most of the 

 plans usually adopted in Europe ; but he had not hitherto observed 

 any hospitals where the views he recommended for quarantine hos- 

 pitals on shore and others for contagious diseases had been intro- 

 duced. 



In chemical lecture rooms, experimental class rooms, and in all 

 manufacturing operations, where acrid, poisonous, or irritating gases 

 and vapors were diffused, he recommended that provision should be 

 made for the direct removal of every offensive product without per- 

 mitting it to escape into the general atmosphere, illustrating this 

 department of the subject by a large plan of the ventilating shafts 

 and flues introduced at his former class-room in Edinburgh. 



From these illustrations it would be seen that the course he recom- 

 mended was a special adaptation in each individual class of building 

 to the purpose for which it was erected, and in unison with the style 

 of architecture adopted. Air could be made to move in any direction 

 that might be required, and when in a proper condition as to tempera- 

 ture and moisture, and in sufficient quantity, many of the details were 

 often matters of indifference. But the economy of each individual 

 movement was a very different question, and extensive ventilating 

 movements could only be most successfully and economically combined 

 when incorporated with the original design before the building is 

 commenced. 



Dr. Reid then passed to the subject of lighting public buildings, 

 and commenced his illustration by throwing a very powerful lime ball 

 light on the flame of candles, lamps, gas-lights, burning alcohol, and 



