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teeth having but a single root are of more frequent occurrence in the skulls 
of lower types, and in only one case was a wisdom-tooth with five fangs 
observed, in a modern skull of high type. As an almost invariable rule the 
third molar of the lower jaw was found to possess two roots, though occa- 
sionally in the higher types four roots were observed. The result of Prof. 
Mantegazza’s investigations strongly corroborates the view put forward by 
Mr. Darwin, and leads the Professor to believe that at some future period 
the third molar may permanently disappear from the human jaw. 
The Colour of Human Hair . — In a paper published in the August 
number of the “ Journal of the Anthropological Institute,” Mr. H. 0. Sorby 
has described the results of some investigations in which he endeavoured to 
separate the pigments contained in the hair, and to subject them to a 
chemical and spectroscopical examination. His researches lead him to the 
conclusion that hair is a colourless horny substance, the tint in different 
specimens being due to the presence of three or perhaps four distinct pig- 
mentary bodies. These pigments being protected by the horny matter of 
the hair, are unaffected by water, alcohol, and other common solvents, and 
sulphuric acid more or less dilute appeared to be the best medium for sepa- 
rating the colouring principles, though, by its agency, it was possible that 
decomposition might be effected, and products be thus formed which were 
not originally present in the hair. This small difficulty was, however, one 
with which so experienced an analyst as Mr. Sorby would have no trouble in 
grappling. From the different kinds of human hair which he examined 
he obtained a reddish, a yellow, and a black pigment, the first of which, 
being an unstable body, may possibly pass into yellow by a process of oxida- 
tion. In bright red hair the red constituent was found to be present unac- 
companied by other pigments ; while dark red hair contains a certain propor- 
tion of the black colouring matter. Golden hair contains less red and more 
yellow colouring matter, while in hair of a sandy tint a proportion of the 
red and black principles are associated with a large quantity of the yellow 
pigment, and in dark brown hair the black principle increases, and the 
yellow and red are greatly reduced in quantity ; until in black hair the two 
latter substances almost disappear, being replaced by the black pigment. In 
some cases, however, as in that of the black hair of a negro, the black 
colouring matter was accompanied by a quantity of the red pigment, equal 
in amount to that found in the bright red hair of Europeans, which leads 
to the conclusion that had the supply of black pigment failed from any cause, 
this negro’s hair instead of being white would have been of as bright a red 
as the hair of the most typical Celt. 
Osteology of the Achinese . — An Achinese skeleton, doubtless the first which 
has ever reached Italy, has lately been presented to the Anthropological 
Museum at Florence, and forms the subject of u Studi Anthropologici intorno 
ad uno Scheletro Accinese,” published by Dr. Ricciardi in the “ Archivio per 
l’Anthropologia.” The people inhabiting the interior of Achin, in the north- 
ern part of the Island of Sumatra, differ in many important respects from 
the neighbouring Battas or Battaks, and have sometimes been regarded as a 
“ cross ” between the Battak and Malay types. The skull examined by Dr. 
Ricciardi agrees, however, most closely with that of a Battak, and has 
a cephalic index of 76'24, so that it belongs to the orthocephalic group of 
