232 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, III

affected. A lethal dose of nicotin causes a depression on the somatic reflexes to the
extent that respiration and other body processes cease.

In the early field application of the capsule treatment, quite a few birds were
killed by leaving capsules in the back of the throat, since many nerve endings are
exposed in this area. Other birds were suffocated by faulty application in that
capsules were introduced into the trachea. When the capsule is placed well into the
crop, very little shock results.

Freeborn concludes that inasmuch as the fullers' earth loses its normal ability
to remain in suspension when subjected to extracts of intestinal washings, there is a
possibility that the direct cause of the nicotin being liberated is due to the derange-
ment of its colloidal system from purely physical factors. It is quite evident that
colloidal chemistry is seriously involved in this phenomenon.

Linsteadt found that certain colloids were safe carriers of nicotin and stated
that molecular weights and sizes are determining factors in the protection granted
to the bird. Since the molecular weight of nicotin (alkaloid) is 162.13 and of
nicotin sulfate 211.17, it is thus seen that the alkaloid nicotin is more toxic to the
bird than nicotin sulfate.

He successfully combined nicotin and casein and determined the molecular
weight as 1297.13, more than six times that of nicotin sulfate making it a safe
carrier. With a thought of overcoming the undesirable features of the nicotin
sulfate capsule, Linsteadt combined 10 per cent. soap with his nicotin caseinate
compound and produced a pellet of a size and shape that it could not enter the
trachea and one which would be slippery when moistened and therefore not stick in
the throat.

Many tests have been employed, by the writer, to determine the efficiency of this
product, called " Nicocides". In no instance has the efficiency fallen below 99 per
cent.

In an attempt to make a dual-purpose Nicocide for both tapeworms and round-
worms, nicotin alginate and crude kamala were combined, using the same amount
of nicotin with one gram of kamala. This has been done without sacrificing the
efficiency of either ingredient when used singly and Freeborn states that the dual
nicocide produces less toxicity than the combining of kamala with nicotin sulfate.
Undoubtedly molecular size is again involved, since nicotin alginate is approxi-
mately six times as heavy as nicotin caseinate and over thirty-seven times that of
nicotin sulfate.

Older than the industry itself is the fight against body lice. Thirty years ago it
was considered standard practice to get birds out of doors in the spring, as soon as
sufficient road dust had accumulated to allow the birds an opportunity to smother