THE HORSE HYGIENE AND SANITARY CONDITIONS. 639 



better dwellings for man and beast are better lighted and better 

 ventilated, and better drained than the old cabin, whose chief 

 comfort was the huge blazing fire on the open hearth. 



Light and Pure Air are essential to health of all animals. 

 The experience of the last generation has brought out many 

 facts to prove that health can not long be secured without them. 

 As long as men lived in open air, or in cabins with huge wood 

 fires, which changed the air of the house every few minutes, all 

 attention to the laws of ventilation and sanitary science was 

 neglected. As soon, however, as better houses were built, and 

 they were heated by close stoves, some plan for artificial venti- 

 lation became necessary. 



In 1830 an experiment in ventilation was made by scientific 

 men at the Foundling Hospital, and at the Zoological Garden, in 

 London. The results achieved were astonishing, and attracted 

 the attention of intelligent men in all parts of the civilized 

 world. By the improved ventilation in the hospital, the length 

 of life of the foundlings was increased one hundred per cent. 

 The same degree of improvement was found in the monkeys' 

 quarters of the zoological garden. Under the old plan the 

 children and monkeys had generally died of tubercles of the 

 lungs and bowels. The impure air of their quarters had too 

 little oxygen and too much carbonic acid. Consumption finds 

 its victims in the homes where the air is impure, and the sun- 

 light and fresh air have not free access. In the North where 

 economy of fuel leads to close houses and stoves, there are more 

 lung diseases than where the houses are open and fires are few, 

 as in the Southern climes. The lesson of confined air often 

 used, teaches that disease must ensue. 



Impure Air Poisonous. In the chapter on anatomy was 

 noted the character of the action of the lungs. By considering 

 the nature of the functions of respiration, we see it consists of 

 two parts viz : inspiration and expiration. By inspiration the 

 air is taken into the cells of the lungs. Around these cells are 

 vast numbers of capillaries or minute blood-vessels, wherein a 

 peculiar work is done, as the impure blood of the system comes 

 to be purified by contact with the oxygen of the air. The blood 



