( 620 j 
until coloured yellow; after removal of the chloroform it was washed 
with alcohol and aqueous potassium hydroxide and finally distilled 
in vacuum. The distillate showed a feebly green colour which 
disappeared by shaking the liquid with a little concentrated sulphuric 
acid which became dark in colour. In this way was finally obtained 
an inactive, colourless and odourless liquid which boils at 267.5° 
(738 mm), solidifies completely when placed in ice and melts at 10°. 
Its sp. gr. taken with the Westphal balance at 26° was 0.766. The 
elementary analysis and eryoscopie determination (in phenol) agree 
with that of a hydrocarbon of the composition C,; Hg». 
Of hydrocarbons with this empirical formula only one is known, 
namely normal pentadecane prepared by Krarrr!) the physical 
constants and properties of which agree in a remarkable manner 
with those of the described substance and I, therefore, do not hesitate 
to declare it identical with the hydrocarbon isolated from the essen- 
tial oil of Kaempferia Galanga. It constitutes more than one-half 
of the liquid portion of the oil. 
I hope to communicate within a reasonable time the results of 
the investigation of the compound which turns violet with bromine, 
of the terpene present in the essential oil and of asubstance remind- 
ing of borneol, after I shall have again at my disposal larger 
quantities of the essential oil which is now being prepared. 
I have to thank Dr. Lone who has assisted me in this investi- 
gation with much zeal and patience. 
Mathematics: — “On series of Polynomials” 2rd part. By Pror. 
J. C. KLUYVER. 
(Communicated in the meeting ot March 29, 1902). 
4. To the region of convergence of series VII for tang—'« the 
greatest possible extension can be given by making a approach 
unity. Then the region Gj is transformed into a band limited by 
two parallel lines through the two singular points +7 and —i, the 
common direction of which is entirely determined by the argument 
of a—l. Now we will examine how, still by application of the 
auxiliar function 
(a—l) a 
a—u 
the region Gj is formed, when an arbitrary function 7 («) characterised 
gu 
’ 
je Berl Ber. 15, 1700, 
