Dr. Herapath on the Optical Characters of certain Alkaloids. 225 
Seipele dispersion found by youin the specimen of cinchonidine sent 
y me. 
Tt may be as well to state that the cinchonidine tested by water 
of chlorine and ammonia gave no evidence of green tint, which it 
would have done if only -3,,dth part of either «-quinine or quinidine 
had been present, according to some recent experiments of my own. 
[ have also found that 1 gr. of pure quinine or quinidine in 35,000 
of water will give an evident “ epipolic’’ appearance ; whilst when 
diluted with 70,000 grs. of water we have still very evident appear- 
ances of “fluorescence”? upon the perpendicular wall of the glass 
vessel exposed to the incident light; whilst a bluish milkiness of 
‘internal dispersion’? may be seen when | gr, of either alkaloid is 
diluted with 700,000 grs. or 1@ gallons of distilled water, well 
acidulated in all these cases with sulphuric acid. 
Some other interesting results have followed from these investiga- 
tions. When quinidine is dissolved in an excess of diluted sulphuric 
acid, and the solution mixed with about twice its bulk of spirit, and 
warmed to 130° F., and tincture of iodine then added in sufficient 
quantity, and subsequently set in repose, beautiful red acicular ery- 
stals are deposited; these, upon recrystallization from rectified spirit, 
acquire an increased size, become beautiful quadrilateral prisms, ex- 
hibiting a deep garnet-red by transmitted light, and possessing a clear 
bluish-purple reflected tint; they are optically doubly absorbent in 
a slight degree, and transmit a brownish-orange body-colour when 
polarized perpendicular to axis. The primary form appears to be a 
rhombic prism ; and as far as my present analyses go, the compound 
seems to possess the following centesimal composition :— 
Jodie see Hou ae 39°665 
Sulphuric acid ............  6°273 
Parnowey 227 GO. S T. 6 ee SEO 
Piydroteny 67.4! Ge) ny 02 3°960 
Mitresen® cs Sicha peo, TRE OOS 
Oxyeent Doria 4 eit 5°040 
Water 8°504 
100°712 
The excess arises from the hydrogen twice calculated in water of 
crystallization. 
These numbers agree very closely with the formula 
(Cs H'? N* Ot + I?) SO3 HO+5H0, 
and prove it to be the sulphate of iodo-quinidine, very analogous to 
the iodo-quinine compound, yet differing materially in its optical 
properties. 
There is another alkaloid frequently associated with quinidine, 
which also crystallizes from spirit in the prismatic form like quinidine 
and cinchonidine, but is another example of epipolism or fluorescence. 
Its iodo-sulphate is deep olive-green in its reflected tint, orange- 
yellow by transmitted light, and possessing in an eminent degree 
optically doubly absorbent powers, thin laminze being quite black, 
but still thinner ones give a bistre-brown “ body-colour’’ when pola- 
rized perpendicular to the axis. 
Phil. Mag. S. 4, Vol. 14. No. 92. Sept. 1857. Q 
