272 
behind the organisms more resistent to heating and which are apt 
to be those forming, as part of their excreted product, alkaline sub- 
stances, which — as the acid forming organisms are not there to 
give them combat — increase to such an extent that the reaction of 
the milk itself becomes distinctly alkaline. 
Ptomaines are chemical substances built on the ammonia type and 
are most commonly produced by bacteria coincidental with an alka- 
line reaction, or in a medium which has previously been made alka- 
line in reaction. Any condition therefore which produces in milk 
or its products circumstances favorable to the production of pto- 
maines is undesirable. The fact that the great majority of reported 
cases of ice cream poisoning are to be traced to the use of cheap grades 
of material would tend to confirm the foregoing supposition, since 
these cheaper grades of ice creams are conmionly made of milk, eggs, 
gelatin, and such thickeners as require heating in order to produce 
the desired result. 
The use of condensed milk in cheap grades of ice cream is by no 
means uncommon. Indeed, with the increased activity of the con- 
densed-milk agent and the increased demand — particularly in large 
cities — for fresh milk, the practice is growing more and more popu- 
lar, and such condensed milks and those substances known as evap- 
orated creams, ■' which are only whole milks concentrated, are far 
too apt to usurp the place of true cream in the manufacture of ice 
creams. 
The contention has been raised by the makers of ice creams that the 
proposed Federal standard of butter fats is too high to be healthful 
and that an ice cream containing the amount of cream required by 
the Federal law can not be digested by many people. They assert, 
however, that an ice cream containing milk, eggs, and sugar, with 
such a thickener as cornstarch or gelatin, can be digested by, and is 
gratefid to, those with whom the true ice cream does not agree. It 
is widely known, howe^'er. among those who have had experience in 
the feeding of invalids, convalescents, and persons having impaired 
digestive organs, that the unification of 3 of our most concentrated 
foods — such as milk, eggs, and cane sugar — jDroduces a combination 
which is difficult of digestion and the feeding of it is often impossible. 
In such cases the patient can assimilate either of the ingredients 
separately, or any two in combination, but the third concentrated 
food when mixed with the other two is more than the organs can 
metabolize. 
Such being the case it would seem doubly desirable from the stand- 
point of the physician and the hygienist that there should be on the 
market a standard preparation consisting exclusively of cream, sugar, 
and flavoring, and of a definite fat content, that he may know what 
is being fed to his patient. 
