360 ANNUAL OF SCIENTIFIC DISCOVERY. 



boiling -water, except continued for a long time, and under pressure, 

 when it suffers disintegration and decomposition. Exposure to the 

 sun will bleach hair, but this will not account for any very sudden 

 change of color. Supporters of the popular opinion refer to changes 

 in the plumage of birds, such as the ptarmigan, and in the hair of 

 certain quadrupeds, such as the mountain hare and ermine, which be- 

 come white towards winter, and of a darker hue when the winter is 

 passed. The belief is rested on, that this is not caused by moulting, 

 or a change of coats, but that it takes place in the existing feathers 

 and hair. But there is no satisfactory evidence of such changes ; and 

 considering the qualities of both, they seem most improbable. There 

 is good proof that in the ptarmigan the change is decidedly connected 

 with moulting ; at least such is the author's decided impression, from 

 inspecting the numerous specimens shot at different seasons be- 

 longing to Mr. Gould, which eminent ornithologist says that the 

 " ptarmigan is always moulting," the changes being from brown in 

 the summer to speckled in the autumn and white in the winter. 

 The speckled feathers, few and large, overlap the white, and as soon 

 as those few are shed the bird appears in its white dress. The similar 

 change amongst quadrupeds most probably arises from the same cause ; 

 and examples, less striking than those amongst wild animals, can be 

 observed in cases of the horse and the cow. Prof. Rolleston, of Ox- 

 ford, had given to the author a portion of the hair of a pony which 

 has been observed to change its coat from tawny to nearly white, in 

 winter. Mr. Erasmus Wilson, who advocates the popular doctrine, 

 refers to the case of a lemming, in support of his views ; but Mr. Blyth, 

 a naturalist, says he examined a lemming killed during its autumnal 

 change, and satisfied himself that " the white hairs were all new, and 

 not the brown changed in color." There are reasons why it might be 

 expected that the summer coat and plumage should be darker than 

 those of the winter. 



The author concludes that, whether we consider one side of the 

 question or the other, the human evidence so questionable, the 

 physiological so much more reliable, the idea of fallacy is unavoid- 

 able as to the hair being subject to sudden change of color from 

 mental impression. The attempts made to explain such a change by 

 physiologists are allowed to be complete failures ; and more amusing 

 attempts had been made to explain the phenomenon on other grounds 

 than those of fallacy. The author, when on foreign service, knew an 

 assistant surgeon of a regiment who had become insane, and whom 

 he visited a fortnight or three, weeks subsequently. The patient's 

 hair, before brown, had become gray ; but when he called attention 

 to the fact, the regimental surgeon simply said, " Your surprise will 



cease when you know that has, since he has been afflicted with 



his tfialady, discontinued dyeing his hair." When we consider how 

 prone the hair of some persons is to turn gray at an early age, even 

 without accompanying or preceding bodily ailment, and how many 

 would wish to conceal this blemish, and so have recourse to chemical 

 means, it is easy to imagine that this source of error may not be un- 

 frequent. Nor should it be overlooked that there is a disposition in 

 some to make statements merely for the sake of exciting momentary 

 surprise, or of acquiring ephemeral notoriety. If we consult the rec- 



