I have been informed, that some tailors’ workshops at Glasgow have been carefully ventilated, and that the immediate results are as satisfactory as were anticipated, but the change has been too recent to permit any estimate of the effects on the general habits of the workmen. The preceding case may serve as a general instance of the practical difference of the effects in the saving of suffering as well as of expense, by active benevolence exerted with foresight in measures of prevention, as compared with benevolence exerted in measures of alleviation of disease after it has occurred. The subscriptions to the benevolent institution for the relief of the aged and infirm tailors, by individual masters in the metropolis, appear to be large and liberal, and amount to upwards of 11,000_l._; yet it is to be observed, that if they or the men had been aware of the effects of vitiated atmospheres on the constitution and general strength, and of the means of ventilation, the practicable gain of money from the gain of labour by that sanitary measure could not have been less in one large shop, employing 200 men, than 100,000_l._ Independently of subscriptions of the whole trade, it would, during their working period of life, have been sufficient, with the enjoyment of greater health and comfort by every workman during the time of work, to have purchased him an annuity of 1_l._ per week for comfortable and respectable self-support during a period of superannuation, commencing soon after _fifty_ years of age. Of that which in these instances appear to be the main cause of premature disease and death, defective ventilation, it is to be remarked that until very lately little had been observed or understood, even by professional men or men of science; and that it is only when the public health is made a matter of public care by a responsible public agency that, what is understood can be expected to be generally and effectually applied for the public protection. Vitiated air not being seen, and air which is pure in winter being cold, the cold is felt and the air is excluded by the workmen. The great desideratum hitherto has been to obtain a circulation of air which was _warm_, as well as fresh. This desideratum has been attained, after much trial, in the House of Commons; but there is reason to believe that, by various means, at an expense within the reach certainly of large places of work, a ventilation equally good might be secured with mutual advantage.