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POPULAR SCIENCE REVIEW. 
worked the rude figures above mentioned. The breccia, being too hard for 
their tools, was left by them exposed as it is now found. M. Lortet does 
not, therefore, regard the makers of the flint implements and the artists of 
the statues as one and the same people ; and he remarks that it is interesting 
to find here within a very limited space the traces of three races which 
have successively inhabited the country, namely, palaeolithic man, the 
Proto-Phenicians, and the Phenicians of historic times, whose works abound 
in the neighbourhood. 
An extra Bone in the Human Wrist. — Dr. Eugene Vincent has found an 
additional (ninth) bone in each wrist of an old Arab. The first row of car- 
pals consisted, as usual, of four bones, but the second row had five ; the sup- 
plementary bone, which was equal in size to the pisiform, was between the 
trapezium and the grande, and it was applied against the scaphoid above and 
the trapezoid in front, but articulated by one of its faces with the second 
metacarpal. The structure was the same in both wrists. The Orang and 
most of the lower Apes regularly possess a ninth bone in the carpus, but this 
differs somewhat in position from the bone found by Dr. Vincent, and does not 
appear to reach the second metacarpal bone which is nearest to it. In the 
Quadrumana, Cuvier considered the supplementary bone to be a separated 
portion of the grande ; but according to the opinion of M. Alix it is rather a 
dismemberment of the scaphoid. Dr. Vincent regards the ninth bone in his 
Arab as probably derived from the trapezoid, which was much reduced in 
size. — ( Compte Rendu de V Assoc. Frang., 1879.) 
ASTRONOMY. 
Secular Acceleration in the Mean Motion of the Moon. — At the April 
meeting of the Royal Astronomical Society, Sir George Airy read a paper 
on the 1 Theoretical value of the Acceleration in the Moon’s Mean Motion in 
Longitude, produced by the change of Eccentricity of the Earth’s Orbit,’ in 
which he advanced the opinion that the true value of this acceleration was 
really 10"T477 per century, and not 6"T8 as generally supposed by astrono- 
mers. The true value of the acceleration in the mean motion of the Moon 
produced by the gradual diminution in eccentricity which the Earth’s orbit 
is undergoing, is a question which was warmly discussed by astronomers 
some twenty years ago, but which has been considered definitely settled 
for the last fifteen years, so that Sir George Airy’s paper created much sur- 
prise. The whole question is purely a mathematical one ; it can only be 
settled by mathematical analyses, and is one about which there ought to be 
no doubt. The existence of a gradual acceleration in the motion of the Moon 
had been known for a long time, but the explanation of its origin had been 
sought in vain by astronomers, until it was discovered by Laplace that the 
diminution of the eccentricity of the Earth’s orbit would produce such an 
acceleration. Laplace calculated its value approximately, omitting a number 
of terms which seemed too small to be sensible, and found it to be equal to 
10"T81G per century, which was in perfect accord with that which seemed 
