The ridiculous and the humorous are very seldom suggested by the senses of smell and taste.

But these senses figure largely in the delusions of the insane, and often painfully - disagreeable odours surround them, or their food tastes badly and is loathed. And it happens that through no other sense are old memories so easily awakened as through the sense of smell. For example, a man enters a room and finds in it an odour which instantly brings up scenes and events of his far away childhood that he seemed to have altogether forgotten, and be is often easily able to connect the odour with the memories it awakens.

The sense of smell has defects which are of great interest, and which have not been much studied. I refer specially to the inability of certain persons to recognise some particular odour, who otherwise possess an acute sense of smell. I know three persons who have never been conscious that a bunch of mignonette had any other odour than that of a bunch of grass, and who cannot perceive any special odour when the wind is blowing towards them over a large bed of mignonette on a day of sunshine; and I know one person who recognises no odour when a soft warm wind is blowing towards him over a field of beans in flower. There appears thus to be what may be called an odour-blindness, if I may coin a word, resembling colour-blindness. But I have not been able to obtain any good evidence that odours or combinations of odours ever seem ludicrous to the mind.

(48) It is often said that deaf-mutes rarely laugh. Regarding this I can speak from personal observation, and I can support my own observations by what has been communicated to me by others.

I have had the opportunity of knowing intimately several highly educated deaf mutes. All of them had good mental powers, and they were all constitutionally bright and amiable. I never knew hearing persons who smiled more frequently or more pleasantly than they did. They were often, however, contented with this silent laughter on seeing a ludicrous occurrence, which provoked loud sonorous laughter in others seeing it who could hear. But all of these deaf-mutes at times laughed audibly and with heartiness, and the movements of the muscles of the chest and face were exactly the same as those which take place in the laughter of the hearing. The character of the sounds, however, was different; but, notwithstanding this difference, they exhibited the same reiteration and were produced in the same manner. I think that I should generally be able to recognise the audible laughter of deaf-mutes, just as I should be able to differentiate the laughter of children from that of grown-up persons. Between the smiling of deaf and that of hearing people there is no difference at all in my opinion, and the laughter of the deaf from tickling has the same peculiarities as their laughter from a special state of mind.

Mr. Howard, a well-known teacher of deaf-mutes, writes that 'the deaf can laugh like others,' and that 'fun, which appeals to the sight, causes them to laugh quite naturally.'

Mr. Elliott, of the Royal Asylum for the Deaf and Dumb Poor, writes that his experience leads him to the conclusion that there is but little difference between the laughter of deaf-mutes and that of ordinary people, though they may not use their voice quite as the hearing do,

Mr. E. A. Illingworth, of the Edinburgh Institution, assures me that deaf-mutes laugh audibly and as heartily as hearing people, though the sound in some cases is rather unnatural.

Another gentleman, who takes much interest in the oral instruction of deaf-mutes, writes that they laugh heartily but never really loud. He attributes this to their not using vocal tones in their articulate speech, and says that oral teachers of the deaf give insufficient attention to voice training, being satisfied with securing articulate sounds. This he thinks may explain the special or characteristic sonorousness of the laughter of those deaf-mutes who have been taught to speak with their mouths.

It is entirely a mistake, therefore, to say that the deaf rarely laugh. Some of them, however, no doubt, especially among the well educated, keep from loud laughing, because they have been told that the sounds they utter are not always pleasant.

(49) As regards those who are born blind as well as deaf, it has been frequently alleged that they never laugh. Their condition in connection with laughtcr has great interest, and I shall endeavour to show, as fully as I can, whether it is or is not correct to say of them that they never laugh. Persons thus afflicted are happily not numerous, hut the cases of some of them have attracted much attention, and as to these my information is fairly complete. Many of the persons who have furnished this information seem not to have had before them the assertion that those who are both deaf and blind from birth never laugh, and their references to the subject are often accidental.

The first blind and deaf person, whose case was much looked into and written about, was James Mitchell, the son of a Scottish clergyman, born in 1795.

He was blind and deaf at birth. His story has been written by Professor Dugald Stewart and by the famous surgeon, James Wardrop, and his condition was regarded by them as unique. He had good intellectual powers. He is frequently spoken of by both of these writers as smiling. In one instance he is said to have 'done' something 'with a joyful smile.' They also frequently say that he laughed. Once it is said that he 'frequently laughs heartily,' and on two special occasions he is spoken of as 'laughing heartily.' All this laughter, however, might have been silent. It is not distinctly said to have been voiced. But Stewart once records that ' he laughed aloud with delight,' and Wardrop records that on one occasion 'he burst into a loud fit of laughter.' It is elsewhere said by Wardrop in his narrative that only when angry did he ' make use of his voice, with which he produced harsh and loud screams.'