219 



ci?ic/ionine-sa]t is ground with about ten times il8 weight of potassium- 

 iodide, and a small amount of water added to the finely pulverized 

 mass. The mixture is alioxyed to stand for 24 hours at room- 

 temperature; the yellow liquid is then sucked otl" as sharply as 

 possible from the precipitate The reddish yellow filtrate is precipitaled 

 t>y 97 " g-alcohol, and the pale yellow precipitate of /}0^j[.yó"m///-rAöf/m?/i- 

 malonate thus formed recrystallised from a little water. During the 

 evaporations on the waterbath a noticeable racemisation does not 

 occur. It is advisable to add as little water as possible during 

 the transformation of the cinchonine-seih by means of potassium-iodide, 

 as otherwise the precipitation with alcohol is very incomplete. 



3. The optically-active components are, like the racemic salt, but 

 in yet higher degree, very soluble; at ordinary temperatures the 

 racemic form is therefore doubtless the stabler phase in comparison 

 with the optically-active components, so that there is no chance to 

 execute a fission by spontaneous crystallisation *}. The solutions possess 

 a beautiful orange or bloodred colour. For a series of wave-lengths 

 the rotations were determined in the case of both antipodes; the 

 values obtained agreed completely in both cases with exception of 

 the algebraic sign. The concentrations of the solutions used in these 

 experiments must be varied over wide limits, if measurements are 

 to be made over a greater spectral range, because the absorption of 

 the light in layei'S of 20 cm. is very intensive. In the visible part 

 of the spectrum no distinct absorption-bands occur; but at both ends 

 it is abruptly cut off-, a 1,5 '/„ solution allows the transmission of 

 waves from 5190 to 6800 A. U. ; a 0,75 "o solution the transmission 

 of the whole red, yellow, green, and blue part of the spectrum 

 to 4870 A. U.; a 0,37 "/„ solution in the same way to 4420 A. U. ; 

 etc. With a 1,48 7o solution these limits were found at: 5020 and 

 6900 A. Ü. 



For the polarimetric determinations we used solutions which contained 

 respectively 1,503 grams (A), 0,511 grams {B), and 0.305 grams 

 (C) of the laevogyrate anhydrous salt in 100 grams of liquid ; in the 

 case of the de.vtrogyreLtovy antipode we used a solution containing 

 0,804 7o of the anhydrous salt. The results of these measurements 

 are reviewed in the following table, and in fig. 2 they are plotted in a 

 diagram. The data have been calculated with respect to the anhydrous salt. 



^) Conf. : F. M. Jaegkr, The Principle of Symmetry and Its Applications to All 

 Natural Sciences, Amsterdam, (1917), p. 209, 210. 



