ZOOLOGY. 359 



the butt at the hip, and endeavor empirically at each distance to in- 

 cline the arm to the proper elevation before firing. Gen. Bonneau de 

 Martray. 



THE QUESTION WHETHER THE HAIR IS OR IS NOT SUBJECT 

 TO SUDDEN CHANGES IN COLOR. 



The following is an abstract of a paper on the above subject, read 

 before the British Association, 1861, by Dr. John Davy : 



The popular notion is decidedly in favor of the affirmative, and 

 many naturalists and physiologists have come to the same conclusion. 

 They adduce instances of the change of the hair to white or gray, in 

 the case of persons under strong emotions of grief or terror. Haller, 

 in his Elementa Physiologies, refers to eight authorities for examples 

 of such changes ; but all that he seems to admit for himself is, that 

 under the influence of impaired health such a change may take place 

 slowly. Marie Antoinette was cited, by favorers of the popular notion, 

 as a striking and well-authenticated instance ; but when fairly con- 

 sidered, the case came under the condition admitted by Haller. Had 

 it been possible for mental emotion, whether of terror or of grief, to 

 render hair suddenly gray, surely in the queen's case the change 

 should have been witnessed at an earlier period than that of the ar- 

 rest of the royal family in their attempt to leave France. If such a 

 sudden change could be presumed, might we not expect to witness it 

 in soldiers engaged in an active campaign, amidst all the dangers and 

 horrors of war ? He had himself examined thousands of soldiers, 

 men prematurely worn out in various climates, and concerned in many 

 a hard-fought battle, many of them grievously wounded; but he 

 never met with an instance of the kind. The case of a rebel Sepoy 

 is stated by Dr. Laycock, on the authority of Surgeon Parry ; it being 

 said that the man's hair changed from black to gray in half an hour. 

 He was undoubtedly under the belief that he would be condemned to 

 death. Might not this be the explanation ? the man was hurried 

 in, profusely perspiring ; he was naked, and cooling and drying rap- 

 idly, his hair, previously gray, being darkened by moisture, resumed 

 its natural color. The effect of water in intensifying color is well 

 known ; and a further circumstance in aid of the explanation given 

 may be found in the fact that the natives of Bengal are in the habit 

 of staining their hair. The Transactions of the Royal Society, ex- 

 tending over two hundred years, do not contain an instance of such 

 change in the color of the hair, a circumstance opposed to the con- 

 clusion that it ever took place ; for had it ever been undoubtedly wit- 

 nessed it is not likely that it would have remained undescribed. The 

 author is not aware that, irrespective of recorded evidence, anything 

 in support of the popular notion can be adduced on physiological 

 grounds. Human hair cannot be injected. Using coloring fluids, such 

 as a solution of nitrate of silver and a solution of iodine, the author 

 has not observed any change of color, except in the portions actually 

 immersed. Whether it owes its color to a fixed oil, to a peculiar ar- 

 rangement of its constitutional molecules, or to both, it resists decay 

 in a remarkable manner ; it resists the action of acids and alkalies, ex- 

 cept the strongest, which dissolve it ; it resists maceration, and even 



