VENTILATION IN WORKSHOPS. 41 



them, arrests the access of noxious vapours to the lungs. These 

 qualities are still further improved by the wool being pressed into a 

 kind of loose cloth such as I show you. Again, chemical and other 

 vapours are rendered comparatively harmless when inhaled through 

 cotton. The vapour of mercury may be made less hurtful to the 

 workmen if the floors of the workshops are sprinkled with 

 ammonia. In the case of all, whose work brings them into con- 

 tact with poisonous metals, certain obvious precautions are neces- 

 sary; such as that the hands and mouth should be washed before 

 eating, and the wearing of a washable overall dress. By all who 

 work among lead, water acidulated with sulphuric acid, should be 

 taken freely as drink. It need hardly be added, that, to the 

 worker in poisonous metals or arts, the constant use of the bath 

 is indispensable to his safety. Efficient, as are these appliances 

 when made use of, we must nevertheless regard them as sub- 

 sidiary to the paramount question of ventilation. In a time, 

 such as ours, when sanitary knowledge is as popular as it is 

 widely diffused, it would be idle to argue that a certain quantity 

 of pure air requires to be inhaled in a given period. The standard 

 amount necessary for each individual to support life and maintain 

 health is, as you know, five hundred cubic feet daily; or, to 

 express it differently, three thousand gallons during that period. 

 In other words, the imperative requirements of health impose on 

 each of us the necessity of inhaling two gallons of good air every 

 minute of our lives. To infringe this rule would be to court 

 disease; and to live in the habitual disregard of it to en- 

 counter premature death. To impress this fact upon your 

 memory, it will 4 only be needful to mention a case or two in point. 

 Dr Edward Smith, the distinguished sanitarian, in his report 

 to the Government on the condition of the London tailors' 

 workrooms, states, that the cubic space in these ill-ventilated 

 places allowed to each operative and the gas-light, is one hundred 

 and fifty-six feet. It is necessary to explain that each burner 

 consumes about as much as an individual. Dr Smith states that 

 the death-rate of the tailors working in these rooms is one-third 

 greater than of persons of the same ages who pursue their occu- 

 pations in good air. Dr Guy, in an inquiry into the health of 



