1180 



TOUCH. 



years ago."* A case of the same kind has 

 been long under the writer's observation ; the 

 subject of it being a gentleman who became 

 blind from amaurosis soon after the age of 

 twenty. His attention having been directed to 

 geology and conchology, he gradually acquired 

 a very complete knowledge of shells both 

 recent and fossil ; being not only able to re- 

 cognise every one of the numerous specimens 

 in his own cabinet, but also to mention the 

 nearest alliances of a shell previously unknown 

 to him. He has occupied himself, moreover, 

 in freeing his fossil shells from their matrix, 

 with a hammer and chisel, knife, &c. ; and 

 has frequently done this with a perfection that 

 could scarcely be surpassed, rarely injuring 

 the specimen with his tools, and generally 

 clearing it completely from its incrustation, 

 where this was practicable. In this way he 

 has succeeded in forming a very valuable col- 

 lection of the fossils of the interesting locality 

 in which he resides. 



A similar exaltation may manifest itself, 

 under the like circumstances, in the general 

 tactile sensibility, both of the surface and in- 

 terior of the body, especially as affected by the 

 vibrations transmitted through solid sub- 

 stances ; whereby a deficiency in the sense of 

 hearing is in some degree supplied. Thus the 

 visitor to a school for the deaf and dumb 

 remarks with surprise that a slight rap given 

 by the master on the table or floor is sufficient 

 to excite the attention of the pupils ; and 

 finds on examination that this is not heard, 

 but is felt by them. A minute account of his 

 personal experience on this head is given by 

 Dr. Kitto ; and as it involves several interest- 

 ing physiological considerations, the principal 

 facts mentioned by him will be here brought 

 under the notice of the reader. " In the state 

 of entire deafness," he remarks, " a peculiar 

 susceptibility of the whole frame to tangible 

 percussions supplies the only intimations which 

 have the slightest approximation to those 

 which hearing affords. I was about to call 

 this a peculiar susceptibility of the sense of 

 touch ; but this would unduly limit a kind 

 of vibration, which, in certain of its develop- 

 ments, seems to pervade the whole frame, to 

 the very bones and marrow. I do not at all 

 imagine that there is in this anything essen- 

 tially different from that which is experienced 

 by those who are in possession of their hear- 

 ing ; but it would seem that the absence of 

 that sense concentrates the attention more 

 exclusively upon the sensation which is 

 through this medium obtained; and the in- 

 timation of which, being no longer checked 

 and verified by the information of higher 

 organs, assume an importance which does not 

 naturally belong to them." This sense of 

 percussion is but little excited in the human 

 body by the vibrations of air ; obviously be- 

 cause there is no expanded surface adapted 

 to receive their influence. Thus Dr. Kitto 

 mentions that the loudest thunder makes 

 no impression upon him, unless it shakes 



* " Lost Senses," vol. ii. p. 215. 



the house in which he is ; in which case 

 it communicates a sensation resembling that 

 produced by the removal of a piece of fur- 

 niture in an adjoining room.* In like man- 

 ner, he is utterly unconscious alike of the 

 sound of bells, and of the vibration produced 

 by their percussion, unless the latter be pro- 

 pagated through solid bodies, as when he places 

 himself in direct contact with a tower in 

 which a powerful peal is being rung. " I re- 

 member," he says, "that once when I was 

 showing a young friend from the country over 

 St. Paul's, we happened to be up examining 

 the great clock, at the very time it began to 

 strike. The sensation which this occasioned 

 was that of very heavy blows upon the fabric 

 in which I stood, communicated to my feet 

 by contact with the floor, and by the feet 

 diffused over the whole body. So," he con- 

 tinues, " guns even powerful cannon 

 make no impression upon this sense, unless 

 I happen to be very near when they are fired ; 

 in that case, I can compare the effect to no- 

 thing better than the sensation produced by 

 a heavy blow upon the head from a fist co- 

 vered with a boxing glove. This effect could 

 only be produced by the tangible percussion 

 of the air, and by the percussion upon the 

 ground transmitted by the feet." So, again, 

 Dr. Kitto states that he is not conscious of 

 even a very loud knock at the door of the 

 room in which he is, unless the door be in 

 such connection with the floor that the per- 

 cussion is communicated through the latter, 

 or unless he be himself in contact with some 

 part of the wall to which it is hung. But, on 

 the other hand, he states, " The drawing 

 of furniture, as tables and sofas, over the 

 floor above or below me, the shutting of 

 doors, and the feet of children at play, 

 distress me far more than the same causes 

 would do if 1 were in actual possession of 

 my hearing. By being to me unattended by 

 any circumstances or preliminaries, they 

 startle dreadfully ; and by the vibration 

 being diffused from the feet over the whole 

 body, they shake the whole nervous system, 

 in a way which even long use has not enabled 

 me to bear. The moving of a table is to rne 

 more than to the reader would be the com- 

 bined noise and vibration of a mail coach 

 drawn over a wooden floor ; the feet of 

 children, like the tramp of horses upon the 

 same floor ; and the shutting of a door like a 

 thunder-clap, shaking the very house. It is 

 by having once heard, that I am enabled to 

 make such comparisons as these, for the 

 illustration of a sensation which one who 

 has never heard, and one who is not deaf, 

 would be alike unable to describe." The 

 fact that the shutting of a door is felt with 

 painful distinctness (as Dr. Kitto elsewhere 

 mentions), even when upon a different floor, 

 whilst the loudest ordinary knocking at the 

 same door is not perceived, very curiously 



* The writer of this article, residing near a rail- 

 way tunnel, has frequently noticed that the emer- 

 gence of a train is indicated by the succussion of 

 the windows of his house, before it becomes audible. 



