Nicotinic Acid 193
her mouth became normal and she could eat. After a few
weeks of building-up in the hospital she was discharged well
enough to walk several miles to her home. Another case
with badly inflamed mouth and vagina, skin sores, paralyzed
legs, and scrambled mind, was dismissed a well woman in
five weeks.
Nicotinic acid is an oxidation product of nicotine, but is
about a thousand times less toxic. In the doses so far used
in human treatments (60 milligrams a day by injection, or
up to 1 gram a day by mouth), it produces no symptoms
except a brief flushing and a little itching and tingling of the
sore areas of skin and mucous membranes. Whether or
not any nicotinic acid is obtained from smoking or chewing
tobacco is doubtful. It is a substance found widely distributed
in Nature in both plants and animals, and like thiamin is
probably necessary to both.
Nicotinic acid is a durable substance, not destroyed by
heat, ordinary acids, or alkalis, nor by exposure to air, so
it is not likely to be injured by ordinary methods of food
preparation. Most leaves contain it, but its distribution in
grains and tubers is very irregular. It has recently been
found that when rootlets are isolated from their parent
plants and cultured in a nutrient solution of glucose and
salts, they require traces of nicotinic acid as well as thiamin
for continued growth. It has also been shown that cut
tobacco leaves with their cut ends in a weak nicotinic acid
solution absorb more water, live longer without wilting, and
make much more nicotine than those in plain water. If
this turns out to be generally true for cut stems and flowers,
nicotinic acid may prove to be a boon to florists as well as to
pellagrins.
The foods which have been found most effective in pre-
venting or curing pellagra, and therefore presumably con-