~Origin.~--These substances are believed to be of an infective
bacterial origin and may be present in foods which are otherwise
seemingly fresh and good. The fact that they cannot be detected in
food without an analysis makes them more of a menace than they would
otherwise be, for any substance which is not discernible to our
senses, the taste, sight, or smell, and which exerts a baleful
influence, such as ptomaine, cannot be anything but a menace to
humanity.

~Infected Food Materials.~--We may congratulate ourselves in the
knowledge that these substances are not present in many foods, and if
we avoid eating nitrogenous materials, which may have become polluted,
either through imperfect canning or by standing in unclean vessels, we
may avoid much of the poisoning which may otherwise be due to the
action of ptomaines.

~Chicken Salad and Ice Cream Poisoning.~--Certain violent attacks of
so-called ptomaine poisoning may be traced to chicken salad which has
been allowed to stand overnight in tin receptacles or to ice cream
which has melted and been re-frozen. In any case the treatment
remains the same.

~Treatment.~--The patient is put to bed and the intestinal tract
cleansed by means of enemas and in many cases purgatives (salts,
castor oil, etc.) as directed by physician.

The symptoms usually present in those suffering from ptomaine
poisoning are nausea, vomiting, dizziness, pain more or less violent
in character, and prostration which is at times alarming.

~Dietetic Treatment.~--The treatment instituted under the
circumstances is very much the same as that used in other forms of
acute poisoning. All food is withheld for a period; the duration of
this starvation must necessarily depend upon the condition of the
patient, the violence of the poison and the extent of the prostration.

~Rectal Feeding.~--When the prostration is great, it is sometimes
necessary to give saline enemas and even rectal alimentation to
prevent collapse.

~Fluid Diet.~--After the violent attack subsides, the patient is
placed upon a fluid diet similar to that used in auto-intoxication and
practically the same as the diet for acute infectious diseases. The
diet must be gradually increased until it becomes normal and the nurse
must remember that the patient is in a condition to suffer a relapse
with the least indiscretion. It is advisable to have a thorough
investigation made to ascertain the source of the original attack,
that the p