OBSERVATIONS ON THE TONGUE. 473 



of its bulk ; and animal mucus one half of its solid contents. 

 It also contains some albumen ; and several saline substances ; 

 as the muriate of soda, and the phosphates of lime, of soda, and 

 of ammonia. 



It is probable that this fluid possesses a solvent power with 

 respect to the articles of food. 



There are small glandular bodies, situated between the 

 masseter and buccinator muscles, opposite to the last molar 

 tooth of the upper jaw, whose nature is not well understood : 

 they are called Glandula molares. They are believed to be 

 mere mucous glands. 



The motions of the tongue are very intelligible to a person who has a prepara- 

 tion of the lower jaw before him, with the tongue in its natural situation, and 

 the muscles which influence it, properly dissected. Its complicated move- 

 ments will appear the necessary result of the action of those muscles upon it, 

 and the os hyoides ; and also upon the larynx, with which the os hyoides is 

 connected. The muscular fibres of the tongue itself are also to be taken 

 into this view, as they act a very important part. 



Although the tongue appears very necessary, in a mechanical point of view, to 

 the articulation of many words, yet there are cases where it has been entirely 

 deficient, in which the parties thus affected, have been able to speak very well 

 in general, as well as to distinguish different tastes.* 



The tongue is also a very delicate organ of touch. We can perceive the form 

 of the teeth, and the state of the surface of the mouth, more accurately by 

 the application of the tongue than of the fingers. 



On the three nerves which go to the tongue, it is generally supposed that the 

 lingual portion of the third branch of the fifth pair is most immediatety con- 

 cerned in the function of tasting, as it passes to the front part of the surface 

 of the tongue. The glosso-pharyngeal are probably concerned in the same 

 function on the posterior part, while the ninth pair of nerves seems principally 

 spent upon the muscular parts of the organ. 



It is obvious that the tongue is most copiously supplied with nerves. This 

 probably accounts for the great facility of its motions, and the power of con- 

 tinuing them. 



* There is a very interesting paper on this subject, in the Memoirs of the Academy of 

 Sciences for the year 1718, by Jussieu ; in which he describes the case of a female fifteen 

 years old, examined by himself, who was born without a tongue. In this paper he refers to 

 another case, described by Rolland, a surgeon of Saumur, of a boy nine years old, whose 

 tongue was destroyed by gangrene. In each of these cases the subject was able to articulate 

 very well, with the exception of a few letters ; and also enjoyed the sense of taste. 



40* 



