THE MEDITERRANEAN N ATURALlTS 
lirms. The rapid inflow of water has in- 
terfered with the work, but the 25 shafts 
(ranging in depth from about 100 to 300 
feet) have now been completed along tne 
line of the tunnel, and the tunnel itself 
(about 6 \ miles long and 14 feet in diame- 
ter) will be finished next year. A canal 
about 30 miles long, and 65 feet deep at its 
lower end, is being opened by one of the 
firms of contractors, and will connect Lake 
Texcoco with the tunnel. An area of about 
350 square miles will be drained by canal 
and tunnel. 
A curious experiment, having as yet no 
satisfactory explanation, has been perfor- 
med by M. Hurmuzescu before the French 
Physical Society. A metallic wire was stret- 
ched horizontally in a glass tube containing 
gas either at ordinary pressure or rarefied. 
When the wire was heated to redness by a 
continuous current, it began to vibrate in a 
vertical plane, and the tube became much 
hotter at the bottom than at the sides. 
Horse meat is quite extensively eaten 
in Several European countries. Its use in 
Paris began July, 18G6, and in 1869 the con- 
sumption was 2758 horses, 65,000 during the 
siege, 5732 in 1872, and 10,619 in 1877. The 
horse butcheries numbered 48 on Jan. 1 , 
1874, and 132 on Jan. 1, 1889. The present 
price of the meat is about half that of beef. 
Horse butcheries are rapidly increasing in 
other French cities, and their output is 
becoming enormous, and even seriously 
affecting the trade in other meats. Horse 
meat is in great favour in Rotterdam, as 
well as in Germany, Denmark, Sweden, and 
t/ ' ' 5 
409 
parts of Italy, although rejected in Turin. 
Regrets have been expressed that it has not 
been adopted in Spain, where it would 
greatly benefit many poor labourers. 
The brain- weights of different races, ac- 
cording to the latest tables, are as follows, 
in ounces; Scotch, 50, 0; German, 49, 6; 
English, 49, 5; French, 47, 9; Zulu, 47, 5; 
Chinese, 47, 2; Pawnee, 47, 1; Italian, 46, 9; 
Hindoo, 45, 1; Gypsy, 44, 8; Bushman, 44, 6; 
Esquimau, 43, 9. The brain of the highest 
apes weighs only 16 ounces. The brains 
of the worst criminals of Paris average 55 
to 60 ounces. 
^PhE inner dark zone of a luminous flame 
has always been looked upon as a space 
where practically nothing is taking place, 
but Prof. V. R. Lewes has proved, as stated 
in a recent Royal Institution lecture, that 
in this portion of the flame the hydro- 
carbons are converted into acetylene, a gas 
which readily decomposes with heat into 
carbon and hydrogen. The decomposition 
takes place in the luminous portion of the 
flame, and it is the liberated carbon which, 
being heated to incandescence, gives the 
light. The outer non-luminous part of the 
flame, instead of being an area of complete 
combustion, is so cooled by the in-rush of 
air that it is extinguished before combustion 
is completed, the products of the incom- 
plete combustion escaping into the air. 
Editor J. H. Cooke. B. Sc.. F.G.S., Malta. 
