When the vapours readily condense to a solid form the condensing plant may take the form of large chambers; such conditions prevail in the manufacture of arsenic, sulphur and lampblack: in the latter case (which, however, is not properly one of distillation) the chamber is hung with sheets on which the pigment collects.
Busch (Ber., 1905, 38, pp. 856, 4049) has isolated a series of bridged ring compounds which he describes as endo-iminodihydrotriazoles, the triphenyl derivative (annexed formula) being prepared by condensing triphenylaminoguanidine with formic acid.
Koerner (Ber., 1884, 17, p. 203) by condensing ortho-nitrobenzaldehyde with aniline, the resulting ortho-nitro-para-diamino-triphenylmethane being reduced to the corresponding orthoamino compound, which on oxidation yields chrysaniline.
Those substituted in the benzene nucleus are obtained by condensing two molecules of a substituted benzyl and benzal chlorides.
The more complex phenazines, such as the naphthophenazines, naphthazines and naphthotolazines, may be prepared by condensing ortho-diamines with ortho-quinones (0.
Uvitic acid, 5-methyl isopthalic acid, is obtained by oxidizing mesitylene or by condensing pyroracemic acid with baryta water.
Xanthene, C13H100, may be synthesized by condensing phenol with ortho-cresol in the presence of aluminium chloride.
The condensing plant varies with the volatility of the distillate.
Such a plate has the power of a condensing lens, and gives an illumination out of all proportion to what could be obtained without it.
It also results on condensing acetylene, and on reducing phenylacetylene by zinc dust and acetic acid.