luable notes;
Migne, _Patrologia Graeca_, cxxxiii.; see also C. Neumann,
_Griechische Geschichtsschreiber im 12. Jahrhundert_ (1888); H. von
Kap-Herr, _Die abendlaendische Politik Kaiser Manuels_ (1881); C.
Krumbacher, _Geschichte der byzantinischen Litteratur_ (1897).

CINNOLIN, C8H6N2, a compound isomeric with phthalazine, prepared by
boiling dihydrocinnolin dissolved in benzene with freshly precipitated
mercuric oxide. The solution is filtered and the hydrochloride of the
base precipitated by alcoholic hydrochloric acid; the free base is
obtained as an oil by adding caustic soda. It may be obtained in white
silky needles, melting at 24-25 deg. C. and containing a molecule of
ether of crystallization by cooling the oil dissolved in ether. The free
base melts at 39 deg. C. It is a strong base, forming stable salts with
mineral acids, and is easily soluble in water and in the ordinary organic
solvents. It has a taste resembling that of chloral hydrate, and leaves
a sharp irritation for some time on the tongue; it is also very
poisonous (M. Busch and A. Rast, _Berichte_, 1897, 30, p. 521). Cinnolin
derivatives are obtained from oxycinnolin carboxylic acid, which is
formed by digesting orthophenyl propiolic acid diazo chloride with
water. Oxycinnolin carboxylic acid on heating gives oxycinnolin, melting
at 225 deg., which with phosphorus pentachloride gives chlorcinnolin.
This substance is reduced by iron filings and sulphuric acid to
dihydrocinnolin.

The relations of these compounds are here shown:--

C-OH C-OH CH
^ ^ ^ ^ ^ ^ ^
/ \_C:C.COOH / \ / \\ / \ / \\ / \ / \\
| | | | C.COOH | | CH | | CH
| | ---> | | | ---> | | | ---> | | |
| |_ | | N | | N | | N
\ / N:N.OH \ / \ // \ / \ // \ / \ //
v v N v N v N

O-phenyl propiolic Oxycinnolin Oxycinnolin Cinnolin
acid diazo hydroxide carboxylic acid

CINO DA PISTOIA (1270-1336), Italian poet and jurist, whose full name
was GUITTONCINO DE' SINIBALDI, was born in Pistoia, of a noble family.
He studied law at Bologna under Dinus Muggelanus (Dino de Rossonis: d.
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