_Observation_. Domestic animals need a supply of pure air as well as man. The cows of cities, that breathe a vitiated air, have, very generally, tubercles. Sheep that are shut in a confined air, die of a disease called the "rot," which is of a tuberculous character. Interest and humanity require that the buildings for animals be properly ventilated. -=-=-=-=-=-=-=-=-=-=-=-= 515. How should rooms be warmed? What is necessary in the adaptation of furnaces to dwelling-houses? -=-=-=-=-=-=-=-=-=-=-=-= CHAPTER XXVI. HYGIENE OF THE RESPIRATORY ORGANS, CONTINUED. 516. The change that is effected in the blood while passing through the lungs, not only depends upon the purity of the air, but the amount inspired. The quantity varies according to the size of the chest, and the movement of the ribs and diaphragm. 517. _The size of the chest and lungs can be reduced by moderate and continued pressure._ This is most easily done in infancy, when the cartilages and ribs are very pliant; yet it can be effected at more advanced periods of life, even after the chest is fully developed. For want of knowledge of the pliant character of the cartilages and ribs in infants, too many mothers, unintentionally, contract their chests, and thus sow the seeds of disease by the close dressing of their offspring. 518. If slight but steady pressure be continued from day to day and from week to week, the ribs will continue to yield more and more, and after the expiration of a few months, the chest will become diminished in size. This will be effected without any suffering of a marked character; but the general health and strength will be impaired. It is not the violent and ephemeral pressure, but the moderate and protracted, that produces the miscalled, "genteel," contracted chests. 519. The style of dress which at the present day is almost universal, is a prolific cause of this deformity. These baneful fashions are copied from the periodicals, so widely circulated, containing a "fashion plate of the latest fashions, from Paris." In every instance; the contracted, deformed, and, as it is called, lady-like waist, is portrayed in all its fascinating loveliness. These periodicals are found on almost every centre-table, and exercise an influence almost omnipotent. If the plates which corrupt the morals are excluded by civil legislation, with the same propriety ought not those to be suppressed that have a tendency so adverse to health? -=-=-=-=-=-=-=-=-=-=-=-= 516. What varies the amount of air received into the lungs? 517. How can the size of the chest be diminished? When is this most easily effected? 518. How are the miscalled, "genteel," contracted chests usually produced? 519. What is said of the style of the dress at the present day? -=-=-=-=-=-=-=-=-=-=-=-= [Illustration: Fig. 100. A correct outline of the Venus de Medici, the beau ideal of female symmetry.] [Illustration: Fig. 101. An outline of a well-corseted modern beauty.