396 THE POPULAR SCIENCE MONTHLY. 



another according to the obstacles opposed by the tongue, the teeth, 

 and the lips. 1 



It has been demonstrated that the sounds of speech are formed in 

 the buccal cavity, by processes which vary within very narrow limits. 

 Authors who have studied in their own persons the pronunciation of 

 the vowels and consonants describe with great minuteness the posi- 

 tions assumed by the lips, the tongue, the soft palate, under all circum- 

 stances, and give drawings which show the various operations we 

 perform while articulating letters and syllables. 3 These observations 

 possess great interest ; but yet the rules thence derived are not so rig- 

 orously true as to be indisputable. As Mandl observes, sounds that 

 are nearly identical are produced with different positions of the organs 

 of speech. If a person has lost all his teeth, he modifies the play of 

 the lips and tongue, and so contrives to speak intelligibly. The voices 

 of persons we know can be imitated so that the deception shall be 

 perfect. By changing the timbre, the voice is made to sound as 

 though it came from a cavern ; this is the ventriloquist's art. Persons 

 who had had the misfortune to lose a considerable portion of their 

 tongue, have been able to converse, though it is not affirmed that 

 hearing them speak would be a pleasure. Some birds find it possible 

 to utter sounds which with us require the use of the lips. In a word, 

 there is nothing absolute in the acts which produce speech, though in 

 general the same organs do not differ very much in their mode of pro- 

 curing the same results, as may be shown from the fact that congeni- 

 tal deaf-mutes who have learned to speak interpret the movements of 

 the mouth with infallible certainty ; they see the speech of the inter- 

 locutor. This proves that our modes of articulation present only 

 shades of difference. 



The phenomenon of deaf-mutes capable of speech has long been 

 esteemed a marvel. In the middle ages there was one instance of 

 this, the credit of which is due to the patience and skill of Beverley, 

 Archbishop of York. In the sixteenth century, the universal scholar, 

 Jerome Cardan, discussed the possibility of teaching the use of the 

 voice to congenital mutes. About the same period, the Spanish 

 monk Pedro de Ponce was, according to an epitaph, famous through- 

 out the whole world for his power of causing mutes to speak. He 

 had for his pupils two brothers and one sister of Pedro de Velasco, 

 and the son of Gaspar de Guerra, Governor of Aragon. Some time 

 later, Juan Pablo Bonet, in a work which is the oldest known upon 

 this subject, treated of the art of giving speech to the dumb. 3 In 



1 sh and th in English ; sch in German ; tch in Russian. 



2 See Ernst Briicke, " Grundziige der Physiologie und Systematik der Spracblaute 

 fur Linguisten und Taubstummenlehrer," Vienna, 1855; Max MUller, "Lectures on the 

 Science of Language ; " Johann Czermak, " Populare physiologische Vortriige," Vienna, 

 1869, etc. 



3 "Abecedario demonstrative : Reduccion de las letras y arte para ensefiar a hablar 

 los Mudos," 1620. 



