375 
ances in young animals. The toxic effect of tlie milk and milk prod- 
ucts of “ nymphomanous ” cows is even more marked. 
Lawrence (reference 79, Part I) has also recently observed the 
passage of typhoid bacilli into the milk of a nursing woman ill with 
typhoid fever. 
Fifth. As shown by Vaughan and others (2), highly toxic sub- 
stances are produced in milk by bacteria. The- earlier investigations 
on the subject of bacterial poisons in milk and milk products were 
confined almost entirely to poisonous cheese, the poisonous properties 
of which were formerly ascribed to various fatty acids. In 1852, 
however, Schlossberger (see Vaughan & Novy, ibid.), from experi- 
ments with pure fatty acids, demonstrated that these substances are 
not sufficiently toxic to account for the highly toxic nature of poison- 
ous cheese. In 1883 and 1884 an epidemic of cheese poisoning 
occurred in Michigan, which led Vaughan and his students to an 
exhaustive investigation of the subject. The outcome of these studies 
was the isolation from poisonous cheese, in 1884, of a crystalline 
substance, to which Vaughan gave the name of tyrotoxicon, and 
which was believed by him to be a diazo derivative of benzene. 
Chemically it was found to be very unstable, its aqueous solution 
decomposing when heated to 90° C. Tyrotoxicon has since been 
isolated, in many instances, from poisonous cheese by other investi- 
gators. It has also been detected in poisonous milk. In 1886 New- 
ton and Wallace (8) found the poison in a milk supply at Long 
Branch which had seriously affected a number of persons. In 1887 
Firth (9), an English army surgeon, isolated it from the milk which 
had poisoned the soldiers of a garrison in India where he was sta- 
tioned, and in the same year Vaughan (10) investigated a number 
of cases of violent milk poisoning occurring at Milan, three of which 
had resulted fatally. Fresh milk, inoculated with the vomit, stomach 
contents, or an aqueous extract of the intestines, gave, after standing 
twenty-four hours at 25°-30° C., a sufficient amount of tyrotoxicon 
to enable these investigators to recognize nitrogen and phenol among 
the products of its decomposition, the latter being recognized by 
precipitation with bromine water and by other well-known tests. In 
these cases the coroner’s jury, before whom this evidence was submitted, 
rendered a verdict of death from poisoning by tyrotoxicon. Camman 
(11) reported 23 cases of milk poisoning attributed to tyrotoxicon, 
and Kinnicutt (12) isolated the poison from milk which had stood 
in unclean vessels for some time. Vaughan and Novy (13) and 
others found tyrotoxicon in poisonous ice cream, and still others have 
obtained it from custards and other desserts prepared from milk 
or cream. Indeed it would appear from these investigations that 
any foodstuff prepared from milk is liable to contain this poison. 
In his later writings on the subject, however, Vaughan (14) takes 
