4 
is 
Be 3 
236 Scientific Intelligence. 
(OOH. a0 
or OH—C—COOH. Barth, the following year, produced it from 
~\ COOH. ' 
pyrocatechin by similar treatment, and maintained that its for- 
mation proved that in benzene one carbon atom must exist united 
to three others; contrary to the hypothesis of Kekulé. This lat- 
ter chemist has now made an elaborate investigation of the 
tronate prepared from tartaric acid, is identical with that obtained - 
from pyrocatechin. It is therefore clear that carboxytartroni¢ 
acid cannot have the constitution hitherto ascribed to it, and 
hence is wrongly named. It should not be called carboxytar 
uncertain owing to the difficulty of obtaining the water of 
stallization, yet no doubt exists that this acid stands in simple 
through this layer as well as by observing it on the side which — 
ne pegeweer together. The method of increasing the ¥} 
ility of the ultra red is closely analogous to that of fluorescence” 
by means of which the ultra violet is made visible. If the wav 
yt 
ous 
ERE cna (Eee Siceaat We he ee 
