3. Economical as to the number of sick to be accommodated on the same floor, so as to save unnecessary waste of time and strength on the stairs to both Ward-Masters and Nurses. Each Nurse should have, in time of peace, not less than from 50–60 patients under her charge. 4. Efficient as to convenient accommodation for Nurses and Ward-Masters, near to the wards of which they are in charge. [Sidenote: 1. Pavilion Plan indispensable on Sanitary grounds. Its Difficulties, on the score of Discipline in Military Hospitals, to be openly met and guarded against.] 1. The Pavilion Plan, while it is incontestably superior, on sanitary grounds, to any other, while it perhaps may be made equally economical, with regard to building, is more expensive than the older crowded and badly-constructed Hospitals, not only as to ground, but because each separate entrance, staircase, set of appurtenances, represents an additional cost of materials, and of hands to keep them clean and in order. Human life is, however, a more expensive article than any other. If human beings, and especially sick human beings, are to be spread over as much space as possible, which is now known to be an essential to health and more especially to recovery, this must be done under any system and can be best done under the Pavilion system. It of course necessarily entails a greater amount and cost of attendance and of supervision. Pure air and light are the prime necessities of a hospital. These are best secured by the Pavilion Plan, and therefore it is the cheapest in the end. As to the hands, there never ought, never will, never can, be a superfluity of hands in a well-regulated Hospital. The duty of the hands consists of two parts--to keep the Hospital clean; to attend the sick. I had rather not enumerate the instances where I have seen that, often from the most various causes, one result arises--that more time and care is given to floors, stairs, &c., &c., &c., than to the sick. Extreme cleanliness is of vital importance; this should be combined with extreme simplicity of detail, and with providing for considerable numbers at once. You can effectually clean a large ward in much less time than two small ones; a long stair than two short ones, &c. Extreme, _not finicking_, cleanliness, thorough ventilation, for which an ample supply of opposite windows will certainly in the long run prove infinitely the best plan, and careful nursing, are probably the main conditions, humanly speaking, of a large proportion of cures--subsidiary to the medical or surgical treatment.