886 Transactions of the American Institute. 



along the ceiling, descending as fast as the lowest stratum of air was 

 carried out of the room by means of openings underneath the stage, 

 which were connected with flues reaching beyond the roof of the 

 building. The main idea being, to produce a circulation and cliange 

 of air, by driving oft' the coldest portion, and substituting for it 

 warm and fresh air. After the exliibitors had explained their 

 apparatus they submitted for consideration the following paper : 



Yentilation of Dwelling-Houses. 



Prof. J. A. Sewall, of Normal University, Normal, Illinois. — Three 

 things are absolutely essential to the physical well-being of man : x\ir, 

 food, and sleep. Deprive him of either of these and he dies. Air 

 and food are material things, to act and to be acted upon in the econ- 

 omy. Sleep is a condition of the nervous system, depending upon 

 the action of air and food. Deprive a man of air and food, and he 

 ceases to sleep ; modify the air and food, and sleep is correspondingly 

 modified. If the air be pure, the food good in quality and sufficient 

 in quantity, other things being equal, the sleep will be sweet and 

 refreshing ; and if the air be impure, the food unwholesome or insuffi- 

 cient in quantity, the sleep will be imperfect, troubled, and dreamy. 

 If the food be good and sufficient, while the air is impure, the food, 

 though good, will not act or be acted upon properly, and, conse- 

 quently, will not nourish the body ; and if the body is not properly 

 nourished and sustained, sleep is imperfect, does not act as " tired 

 nature's sweet restorer." Then, on the air we breathe depends all 

 that is essential to our physical well-being or health. It is the breath 

 of life. 



Experience teaches the same fact. The lumberman of our northern 

 pine forests, in his camp of boughs, his diet of beans and pork, lard 

 and molasses (food that is ordinarily regarded not the most whole- 

 some), whose habits are not altogether the best, is always strong, 

 robust, and most nearly free from all the ills that flesh is heir to. 

 His food is coarse, his work is hard and exhausting, and he is exposed 

 to cold wind and storm ; jei his breath in the forest by day, and in 

 tfie camp by night, is the pure life-giving air of heaven ; and, breath- 

 ing this, his food is well digested, his sleep refreshing, and bare 

 existence is to him a pleasure. 



Now, army statistics show that the field hospital is fiir better for 

 sick and wounded soldiers than the best constructed and best man- 

 aged post hospitals. Though in the latter, every comfort and con- 



