THE VOCAL APPARATUS 



148 



196. Dumbness is most frequently due to deafness. The 

 auditory word center has never been stimulated. In 

 recent years it has been found 

 possible to stimulate the speech 

 center through its connection 

 with the visual center. Chil- 

 dren born deaf are taught to 

 imitate the movements of the 

 mouth, tongue, and throat of 

 one who speaks, and speech 

 results from these remembered 

 movements acting upon the 

 speech center. 



197. . Care of Throat and Voice. 

 If the delicate lining mem- 

 brane of the larynx becomes in- 

 flamed through " taking cold " 

 or from exposure to dust or 

 irritating gases or from over- 

 use or strain of the vocal 

 cords, the voice is injured and 

 its use may become painful 

 or impossible. These causes 

 should be avoided. When a 

 daily cold bath is not practi- 

 cable, a dash of cold water over the neck on rising in 

 the morning will prove a tonic for the throat and help 

 to avert colds, hoarseness, and sore throat. Breathing 

 should be through the nose, and not through the mouth, 

 and children should be trained in infancy to sleep with 

 the mouth closed. In going from the warm air of the 

 house into the cold outer air in winter the precaution 

 of closing the mouth is especially to be observed. Pass 



Fig. 84. Diagram of the path 

 of the nervous impulses in 

 writing from dictation. 



Au C center of hearing. 

 MC motor center. 

 OC sight center. 



