55 
Numerous experiments have been made to improve the aroma of 
poor tobacco. Ovxidizing media have been applied to destroy supposed 
injurious by-products. The writer tested the action of a 1 per cent 
solution of potassium permanganate for five minutes, but the results 
were not encouraging, on account of the injury to certain other 
properties. 
Other methods consist in the application of substances of powerful 
aroma. For example, we find among the ingredients for the preparation 
of petuning liquids anise seed, cloves, cinnamon, coffee, and tincture of 
valerian.! In Cuba tonka beans and vanilla beans are also used to 
improve the aroma, but with very rank tobaccos even such ingredients 
prove insufficient. The important question of how to improve poor 
products deserves careful attention and further detailed study. 
NITRITE CONTAINED IN SWEATED TOBACCO. 
Although the tobacco of commerce has been the object of frequent 
and numerous analyses, one compound occasionally occurring in it has 
thus far been entirely overlooked. It is the nitrous acid present in the 
form of nitrites. While nitrates frequently occur in various living 
plants and also in fresh tobacco leaves, nitrites do not. Indeed, these 
salts would act very poisonously on the living cells if they accumu- 
lated to even a small degree. The writer has observed that the poison- 
ous character of free nitrous acid is so great that it kills algve after one 
day, even at a dilution of 1 part to 100,000 parts, although its acid 
character is so weak that it is easily liberated from the nitrites by 
dilute organic acids, such, for example, as are contained in the cell sap 
of most plants; hence the salts of nitrous acid are also very strong 
poisons wherever an acid-cell sap in the plants can liberate nitrous acid 
from them. 
When tobacco leaves rich in nitrates, however, are subjected to the 
sweating process after being cured a portion of the nitrates is reduced, 
whereby, as an intermediate step, nitrites are formed, ammonia repre- 
senting the final product. Some sweated tobaccos are so rich in nitrite 
that a concentrated extract, even when prepared in the cold, gives a 
decided odor of nitrous acid upon the addition of sulphurie acid, and 
even the smallest quantity of the extract produces at once separation of 
iodine from potassium iodide on addition of a little sulphuric acid. 
When upon dilution the brown coloration of the tobacco extract is 
sufficiently diminished, the well-known test of Gries for nitrites is also 
easily obtained. The tobacco extract containing nitrites gives a blue 
reaction with tincture of guaiac, but this reaction of nitrous acid is also 
obtained after boiling the extract for a minute, while the similar blue 
reaction caused by oxidase is made impossible after heating the extract 
a short time to 67° C. (153° F.), or, if the extract is weakly alkaline, 
’ Report No. 62 (p. 17), U. S. Department of Agriculture. Marcus L, Floyd, 
