[TINGLE-FERGUSON] AQUEOUS SOLUTIONS OF NICOTINE 25 
Further, Emery gives no indication of how he purified the nicotine 
he employed. Any impurity left in his nicotine would tend to make 
his determinations differ from ours in exactly the sense that they do. 
The difference between_us is, however, very small. 
Our results, expressed as they are in Ventzke Sugar scale divisions 
for ‘‘j’’ light may be converted into circular degrees by those who 
find that system of measurement more convenient, using the 
factor 1 V sugar scale div.=0-3906 circular degree. It is to be 
noted, however, that the circular measurements so calculated are 
not identical with the figures which would be obtained by working 
with “D” light, so that their utility is limited almost entirely to the 
analytical purposes to serve which this work was undertaken. 
If we may assume that Popovici worked with the same light 
that we employed, it will be seen that his nicotine had a much lower 
“rotatory power than ours.. He gives for a 1% nicotine solution a 
rotation of 1° 29’ circular measure, whilst our determinations show ~ 
that this should be 1° 57’. This difference would be accounted for 
if his nicotine was impure, or if he used “D” light. 
