Dr. Marshall Hall on Stammering. 257 



4. Into those, in the articulation of which the expired air is 

 not interrupted, and scarcely impeded at all. 

 Of the first class, are 



B D G* 



p ; T ; K . 



In tracing these letters into their sub-divisions, we may 

 observe, that the first pair are labials, being formed by the 

 lips compressed together ; the second pair are linguo-dentals, 

 formed by pressing the point of the tongue against the posterior 

 and upper part of the upper teeth ; and the third pair are 

 linguo-palatal, being effected by pressing the middle part of the 

 tongue against the palate. In all, the posterior apertures of 

 the nostrils are effectually closed by the pendulous vail of the 

 palate being drawn upwards, and accurately applied to their 

 posterior apertures. And of course, those persons whose 

 palate is perforated, or in whom the pendulous vail of the 

 palate is imperfect, as sometimes arises from disease, are more 

 or less incapacitated from pronouncing these letters, the expired 

 air being no longer intercepted, as it ought to be, in its course. 



Of the second class, are 



F S 



y ; theTHf; and z . 



In the articulation of these letters, the posterior orifices of 

 the nostrils are required to be closed, whilst, in the first pair, 

 the compressed air is continually forced between the upper 

 teeth and under lip ; in the second, between the teeth and the 

 tongue ; and in the third, between the point of the tongue and 

 the anterior part of the palate. 



From this view of the subject, it will be readily apprehended 

 how the substitution of D or T for the TH, by foreigners, is so 

 remarkable ; for it is no less than the substitution of a total 

 interruption, for a mere compression of the air, in its exit from 

 the chest. 



Of the third class of letters, are 



M; N; L; R. 



In the enunciation of these letters, the expired air is only 

 very slightly compressed, the nostrils being left freely open. 

 It is for this very reason, probably, that these letters have been 



* i, e. the hard G. f Hard and soft. 



