Observations and Experiments on the Sense of Taste. 249 



eating, I do not taste any thing but while the breath is 

 going out : and I suppose I should have observed that be- 

 fore now, if it was more easy and natural, than it is, to- 

 take notice spontaneously, without endeavouring at it, when 

 the breath is coming in and when it is going out ; but in fact 

 we are seldom led to remark at what moment the change 

 from inspiration to expiration, or vice versa, is taking place. 



I next tried the experiment with zinc and silver on the 

 tongue ; the process usually referred to in lectures on galva- 

 nism. I considered, that if that sensation should prove to be ? 

 while the tongue is between the metals, what one would com- 

 monly call a taste, and not merely a feel, it would destroy 

 my supposition ; because it seems clear, that the tongue alone, 

 and not the nose, could be the organ of this sensation which 

 is produced by the galvanic action transmitted through it : 

 unless, indeed, we could suppose some vapour to be generat- 

 ed : but that it would equally, or even more, destroy another 

 supposition, which, I believe, is generally received among ob- 

 serving persons, upon the common notion of the taste, viz. 

 that no taste can happen without touching the palate or roof 

 of the mouth ; since here the tongue is to be kept confined. 

 I saw in " Conversations on Chemistry,'''' and I suppose it is 

 so in other similar books, that the sensation produced by 

 this experiment is called " a taste accompanied with heat ;" 

 but I did not mind the name ; because, as we are commonly 

 told that our tongue is the peculiar seat of taste, any pecu- 

 liar sensation, of which the tongue was the exclusive seat, 

 might very naturally come to be called so ; and I believe the 

 peculiar sensation produced by these metals in this way, is a 

 sensation exclusively confined to the tongue ; in truth, it is not 

 easy to find any other place where this galvanic experiment 

 can be tried ; since the metals must be applied on two sides, 

 and near ; unless we were to skin one of our fingers for the 

 purpose ; for the skin prevents the action ; at least, I did not 

 find it succeeded when tried on part of the moist inner sur- 

 face of the lip doubled together, or on the two sides of the 

 gums. 



When tried on the tongue, with a half-crown piece and a 

 plate of zinc, I think the sensation while the tongue is be- 



