Sympathetic relations exist throughout the whole human system, and especially between different parts of the same organ; if one part of the mucous membrane is injured, another part is as liable to suffer as that immediately injured. If congestion takes place in any part of this mucous membrane, it may cause congestion in some remote part of the membrane, without affecting the intervening parts. There is a certain common misuse of the voice which creates in the pharynx an irritation called “clergyman’s sore throat.” By the law of sympathy, this congestion is likely to be communicated from the pharynx to the mucous membrane of the stomach. It may also attack the mucous membrane of the bronchial tubes and through them affect the lungs. Although this disease caused by the misuse of the voice is called “clergyman’s sore throat,” it is not confined to clergymen; it prevails to a considerable extent among school teachers, lawyers, and auctioneers. It is dangerous for one to enter upon any form of public speaking without having a sufficient knowledge of the voice to use his own correctly. This is true not merely because it gives power to speak more effectively, but because it enables one to preserve his own health, and thereby prolong his usefulness. “Clergyman’s sore throat” is caused by making too close a chamber of resonance in the pharynx while speaking. This is a confirmed habit with a very large number of persons; in fact, it might almost be said to be a prevailing difficulty, but it does not always cause a sore throat until the voice is more constantly used than it ordinarily is in private life. A clergyman or others may for years have practised this habit without feeling the effect upon the throat; but as soon as they come to speak steadily for a half hour or more, and that, too, for the purpose of being heard in a large room, begin to realize a huskiness which soon develops into an irritation of the throat. This finally develops into a congestion, and sooner or later into a cough, which results in the breaking down of the powers of the individual, and if it does not receive immediate and proper attention consumption may be the result. No medicine, however good, can give more than a temporary relief. So long as the cause (which is the misuse of the voice), remains, the difficulty must return. Sometimes “clergyman’s sore throat” is not introduced by huskiness; the first symptom observed is that of dryness or irritation. This is especially true if the voice is characterized by a metallic element. All these evils can be cured by proper vocal education, providing the patient does not wait too long. [Illustration: =CONVOLUTIONS AND FISSURES OF THE OUTER SURFACE OF THE CEREBRAL HEMISPHERE.=] =_RELATION OF THE PROPER USE OF THE VOICE TO THE NERVOUS SYSTEM._= The vocal organs may be said to be tools, and the nerves the workmen appointed to use them.