68 Scientific Intelligence. 
either on neutralizing with an acid or on the addition of alcohol, 
has made a systematic examination of the substance thus obtained. 
brown solution on saturation with deposited a whitish 
oe ae ee Alcohol acted similarly but the filtration 
was easier. After washing with alcohol and dryin 
Soomicused fitteen per cent of the wood used. As it i like a 
ed 
with ammonia, and then with the soda. It afforded on scale 
carbon 44°6, hydrogen 6°4, corresponding to the forasalk C.H,,0.. 
Comparative examinations of the quantity of this substance in 
various woods were then made, and the kinds examined by 
oauitaae acid method arranged themselves in the following order 
in this respect: birch, ash, alder, cherry, white beech, oak, pea 
beech, ste willow, horse-chestnu t, maple and pine, the last. cere 
ing only traces. The quantity was greater the nearer to the center 
of the tree the specimen was taken. ood-gum is insoluble in 
Ch., IL, xix, 146, March G. F. B. 
8. Dust Figures produced by Sound Waves —Her. K. H. Sa 8 
BacH and E, E. Borum extend the work of Profsssara E. Mac 
oes Fischer on the reflexion and refraction of sound sentaiand o in 
sulphuric acid, does not reduce the rl ae test, and rotates to the 
lett.—J. prakt. 
a ous to those 
The latter seeder however, gives a much more interesting way 
of yin waves by actually illuminating, so to speak, the 
wave iteel ante a der Physik und Chemie, No. 5, 1879, p. 1. 
a 3s 
9. Continuous Spectrum of Electric Sparke.—Professor ANTON 
Azr shows that she spectrum 0 of the electric spar ark between ~~ 
con 
spectrum to the particles of the metals of the electrodes 
to a white heat but not to tthe gaseous condition which po 
