IN HYGIENIC PHYSIOLOGY. 165 



27. Should afire-place be closed? 



(See Physiology, p. 99.) 

 No. It is a most efficient means of ventilation. 



28. Why does embarrassment or fright cause a stam- 

 merer to stutter still more painfully ? 



Stuttering is mainly a nervous disorder, and hence any ex- 

 citement tends to increase the impediment of the speech. 



29. In the organs of voice, what parts have somewhat 

 the same office as the case of a violin and the sounding- 

 board of a piano ? 



(See Popular Physics, p. 186.) 



The pharynx, the mouth, and the nasal passages all act by 

 resonance to modify the voice. 



30. Why should tve be careful not to " take the breath 9 ' 

 of a sick person ? 



Because, in this manner, special disease germs may be di- 

 rectly transferred from the lungs of the sick person into our 

 own. It is well never to "take the breath" of any person, 

 sick or well, since impurities are constantly passing off from 

 every human system through the avenue of the lungs. 



31. What special care should be taken with regard to 

 keeping a cellar clean ? 



The walls and floor should be free from moisture, and any ac- 

 cumulation whatever of dust or refuse. There should be not only 

 some means of constant ventilation, but the windows ought fre- 

 quently to be opened to full currents of air from without. 

 Vegetables should never be allowed to decay in the cellar. In these 

 days of furnaces, when, in addition to the ordinary upward 

 travel of cellar odors, the sides of the registers in the rooms 

 above afford a direct means of ascent for all the foul or stag- 

 nant air that may lurk below, the basement should be the 

 sweetest and most immaculate portion of the house. 



32. How is the air strained as it passes into the lungs ? 



The constant motion of the cilia, which line the air-pas- 

 sages, produces an outward current, which arrests and expels 



