266 G. CARR ROBINSON AND W. L. GOODWIN ON 
five complete fractionations had been made, whilst in the second experiment only 
sixteen fractionations were made; and it was the desire of more completely 
isolating the higher members of this series, and, if possible, ascertaining their 
true position in the series by longer continued fractional distillation, that has 
given rise to the present paper. ’ 
In order to carry out this investigation, we were again kindly supplied by 
Messrs GELLATLY and THomson with a quantity of crude bases, about one 
gallon; these were purified as follows:—the crude bases, being a mixture 
chiefly of bases, tarry matter, and paraffin, were digested for several hours with 
dilute sulphuric acid, the insoluble portion separated by filtration, and the acid 
liquor neutralised with caustic soda; the so-separated bases were again dis- 
solved in dilute sulphuric acid, again treated with caustic soda, and this process 
repeated other three times, when the mixture of bases was considered suffi- 
ciently pure to be distilled. After eight distillations, a large quantity of black 
tarry matter being left in the still from each operation, fractional distillation 
was commenced. 
Fractional Distillation of the Mixed Bases. 
After twelve complete fractionations, fractions ranging from 250°C. to 
390° C. about 5 germs. of fraction 260°-270° C. was dissolved in strong nitric 
acid, the solution evaporated to dryness on water-bath, the residue treated with 
water, and to the aqueous solution, cooled in freezing mixture, platinum 
chloride added. The precipitated platinum salt was washed with ice-cold 
water, then with a mixture of alcohol and ether, dried over sulphuric acid and 
finally at 100° C. 
Analysis gave— 
I. 25:52 per cent. platinum. 
II. 25:55 55 
” 
Fractional distillation was then continued to twenty times and platinum 
salts prepared from fractions 270°-275° and from fraction 290°-295° in same 
manner as from 260°-270". 
Analysis of platinum salt from fraction 270°-275°— 
I. 24°74 per cent. platinum. 
II. 24°63 ‘5 5 
This fraction might be expected to contain Cryptidine, C,,H,,N, and as the — 
chloroplatinate of that base, 2C,HiNHCI, PtCl, requires 27:13 per cent. 
platinum, the small percentage of platinum was quite inexplicable, except on 
the assumption that during the process of evaporating with nitric acid a nitro- 
substitution compound had been formed. Assuming that one atom of hydrogen 
