258 Scientific Intelligence. 
amples: aleohol by losing 2 equivalents of hydrogen is turned into al- 
dehyde : ate Van a Mg eV a: ‘ 
Glycol, on the other hand, by giving up 2 equivalents of water, is con- 
verted into glycolic ether (oxyd of ethylene) : 
C, H, 0, O,=¢, HO... 
Glycolic ether and aldehyde are isomeric; their composition is the 
same, but their properties, both physical and chemical, are extremely 
different. This is a good case of kenomerism. Again, essence of tere- 
benthine combines with hydrochloric acid under different conditions to 
form two distinct hydrochlorates, the monohydrochlorate, C,, H,, H Cl, 
and the dihydrochlorate, C,,H,,2HCl. From the first body the 
crystalline compound C,, H,,, camphene, is obtained, and from the lat- 
ter C,, H,,, terpilene, two hydrocarbons of very different properties.— 
Reader, July 7. 
6. 
e 
and besides is admirably adapted for the class-room. 
After having enlarged our knowledge of longitudinal vibrations of 
glass tubes coated on the inside with lycopodium, Mr. Kundt closed one 
or both ends of the longitudinally vibrating glass tube; instead of the 
between the heaps, produced by the stationary waves are corresponding 
parts of the wave-length of the tone in glass and air (here one-half 
2 Waves in glass, thus giving 4:16—=1:32—%: 48. 
When the tube is held in the same manner, that is, when its length is 
the same part of a glass-wave, the distance of the heaps (half-wave lengths 
in the gas) will be proportional to the velocity of sound in the gas, or 
the number of heaps will be inversely proportional ‘o that velocity. 
