BULLETIN No. 90a. 
7 
METHODS OF ANALYSIS. 
Tobacco analysis has received but little attention in this country, 
hence we have adopted no official methods of analysis. Many of 
the methods now in use are old, and while some are good others are 
quite inaccurate. It has been the purpose in selecting the methods 
used in this bulletin to choose those which would be of practical 
application, combined with simplicity and accuracy. 
The basis of the following scheme of analysis is compiled from 
the methods of Grandeau, Schloessing, Fresenius, Nessler, Patterson, 
Kessling, Association of Official Agricultural Chemists, and the 
Sixth Annual Report of the New York Station, to which modifica¬ 
tions and additions have been made. 
Organic Analysis. 
Preparation of Samples .—The cured leaves are stemmed, and then 
allowed to thoroughly dry at the temperature of the grinding-room. 
The two portions are then weighed, ground so as to pass through a 
1-36 inch sieve, and preserved in air-light jars. The grinding will 
have to be done on a very dry day, or the tobacco will become too 
wet to handle. The different determinations are to be made from 
these finely-ground air dry samples, and the results afterwards cal¬ 
culated to water-free basis. 
Moisture .—Two to three grams are dried for four hours, heating 
fully to the temperature of boiling water. 
Nicotine .—Take 5 to 10 grams tobacco, and thoroughly saturate 
it with an alpoholic solution of soda (6 grams NaO H in 40 c. c. H 2 O 
and 60 c. c. 95 per cent, alcohol.) Allow this to stand for several hours 
to partially dry out and drive off the ammonia. Then transfer to 
an extractor and extract with ether for 8 hours, collecting the extract 
in a 300 c. c. flask The extract is then made slightly acid with sul¬ 
phuric acid, and the ether evaporated off, using a very gentle heat. 
To this residue add 150 to 200 c. c. diluted soda hydrate solution 
(4:100), and distill off (he nicotine. Titrate the distillate with IL sul¬ 
phuric acid, cochineal being used as an indicator. Forty-nine 
- v 49) parts by weight of H 2 S0 4 being equal to 162 parts by weight 
of nicotine. 
Nitric acid ( Qualitative ).—The qualitative test is made as follows: 
Two or three grams of the substance are placed in a beaker, 
thoroughly mixed with a small amount of water, and allowed to 
stand for a short time. This is then filtered off, and a few drops are 
placed on a porcelain crucible cover; a few drops of concentrated 
sulphuric acid, in which some brucine has been dissolved, is now 
brought on the cover, and the two solutions are allowed to mix. If 
