exceed in importance all other specific diseases previously
referred to. These troubles have generally been explained as produced by
bacteria of the putrefactive class which find their way into the milk
through the introduction of filth and dirt at time of milking.[120]
Fluegge[121] has demonstrated that certain peptonizing species possess
toxic properties for animals. Recent experimental inquiry[122] has
demonstrated that the dysentery bacillus (Shiga) probably bears a causal
relation to some of these summer complaints.

~Ptomaine poisoning.~ Many cases of poisoning from food products are also
reported with adults. These are due to the formation of various toxic
products, generally ptomaines, that are produced as a result of
infection of foods by different bacteria. One of these substances,
_tyrotoxicon_, was isolated by Vaughan[123] from cheese and various
other products of milk, and found to possess the property of producing
symptoms of poisoning similar to those that are noted in such cases. He
attributes the production of this toxic effect to the decomposition of
the elements in the milk induced by putrefactive forms of bacteria that
develop where milk is improperly kept.[124] Often outbreaks of this
character[125] assume the proportions of an epidemic, where a large
number of persons use the tainted food.

FOOTNOTES:

[78] Hart, Trans. Int. Med. Cong., London, 1881, 4:491-544.

[79] Freeman, Med. Rec., March 28, 1896.

[80] Busey and Kober, Rept. Health Off. of Dist. of Col., Washington, D.
C., 1895, p. 299. These authors present in this report an elaborate
article on morbific and infectious milk, giving a very complete
bibliography of 180 numbers. They append to Hart's list (which is
published in full) additional outbreaks which have occurred since,
together with full data as to extent of epidemic, circumstances
governing the outbreak, as well as name of original reporter and
reference.

[81] Smith, Theo., Journ. of Expt. Med., 1898, 3:451.

[82] Dinwiddie, Bull. 57, Ark. Expt. Stat., June, 1899; Ravenel, Univ.
of Penn. Med. Bull., Sept. 1901.

[83] Ravenel, Journ. of Comp. Med. & Vet. Arch., Dec. 1897; Hartzell,
Journ. Amer. Med. Ass'n, April 16, 1898.

[84] Stille, Brit. Med. Journ., Aug. 19, 1899.

[85] This test is made by injecting into the animal a small quantity of
tuberculin, which is a sterilized glycerin extract of cultures of the
tubercle bacillus. In a tuberculous animal, even in the very