NATURAL HISTORY. 



833 



grcss of the infusion, in the oppo- 

 site direction ; and my success here 

 much exceeded my hopes. 



A section of the potatoe presents 

 four distinct substances : the inter- 

 nal part, which, from the mode of 

 its formation and subsequent office, 

 I conceive to be allied to the al- 

 burnum of ligneous plants ; the bark 

 Avhich surrounds this substance ; the 

 true skin of the plant ; and the 

 epidermis. Making transverse sec- 

 tions of the tubers, which had been 

 the subjects of the experiments, 

 I found that the coloured infusion 

 had passed through an elaborate 

 series of vessels, between the cortical 

 and alburnous substance, and that 

 many minute ramifications of these 

 vessels approached the external 

 skin, at the base of the buds, to 

 ■which, as to every other part of the 

 growing tuber, I conclude they con- 

 vey nourishment. 



Observations on the Structure of the 

 Tongue; illustrated ly Cases in 

 ukkli a Portion of that Organ has 

 been re7iioied by Ligature. By 

 Everard Home, Esq. F. R. S. 



Physiological enquiries have ever 

 been considered as deserving the at- 

 tention of this learned society, and 

 whenever medical practitioners, in 

 the treatment of diseases, have met 

 with any circumstance which threw 

 light upon the natural structure or 

 actions of any of the organs of the 

 human body, or those of other ani- 

 mals, their communications have met 

 with a favourable reception. 



The following observations derive 

 their real importance from offering 

 a safe and effectual means of remov- 

 ing a portion of the tongue, when 

 that organ has taken on a diseased 



Vol-. XLVU. 



action, the cure of which is not with- 

 in the reach of medicine ; and, as 

 the tongue, like many other glandu- 

 lar structures, is liable to be affected 

 by cancer, it becomes of no small 

 importance that the fact should be 

 generally known. In a physiolo- 

 gical view, they tend to show that 

 internal structure of the tongue is 

 not of that delicate and sensible na- 

 ture which, from its being the organ 

 of taste, we should be led to imagine. 

 The tongue is made up of fasicuH 

 of muscular fibres, with an interme- 

 diate substance met with in no other 

 part of the body, and a vast number 

 of small glands ; it has large nerves 

 passing through it ; and the tip pos- 

 sesses great sensibility, fitting it for 

 the purpose of taste. 



Whether the sense of taste is con- 

 fined entirely to the point of the 

 tongue, and the other parts are made 

 up of muscles fitted for giving it mo- 

 tion ; or whether the whole tongue 

 is to be considered the organ, and 

 the soft matter which pervades its 

 substance and fills the interstices be- 

 tween the fa^icuii of mnscular fibres, 

 is to be considered as connected with 

 sensation, has not, I believe, been 

 ascertained. 



The tongue, throughout its sub- 

 stance, has always been considered, 

 by physiologists, as a very delicate 

 organ ; and it was believed, that 

 any injury committed upon it would 

 not only produce great local irrita- 

 tion, but also affect, in a violent 

 degree, the general system of the 

 body. This was my own opinion, 

 till 1 met with the following case, 

 the circumstances of which induced 

 me to see this organ in a different 

 point of view. 



A gentleman, by an accident 



which it is unnecessary to describe, 



had his tongue bitten with great vio- 



3 U lence. 



