599 
inert it is a limitation, not a disadvantage of the process. If heat- 
resisting poisons are present in milk the raw product will be quite as 
toxic as the heated, probably more so, for the heat may check the fur- 
ther production of such substances by its destructive action upon 
bacteria. 
At first, “ sterilization ” at or above the boiling point was at- 
tempted. It was soon shown that it was exceedingly difficult to ster- 
ilize milk on account of the resistant spores, and further, that a high 
degree of heat may produce undesirable changes. A more precise 
knowledge of the “Objects to be attained has gradually resulted in low- 
ering the temperature and shortening the time. Temperatures varying 
from 95° to G0° C., and periods varying from a moment to two hours, 
have been variously recommended for the pasteurization of milk. As 
a rule the controlling factor is the thermal death point of the tubercle 
bacillus. 
The temperature and time determined by various authorities for 
milk pasteurization follows: 
Authorities. 
Year. 
Tempera- 
ture. 
Time. 
Freeman a 
1898 
68° C. 
30 minutes. 
Freeman b 
1907 
60° C. 
40 
do. 
Forster c 
1892 
70° C. 
5-10 
do. 
Smith, Th.d 
1899 
60° C. 
20 
do. 
Oppenheimer * 
1899 
70° C. 
30 « 
do. 
Hippius / 
1905 
60° C. 
60 
do. 
Bitter 9 
1890 
68-69° C. 
30 
do. 
Hesse A 
1900 
60° C. 
15-20 
do. 
Russell & Hastings i 
1900 
60° C, 
20 ' 
do. 
« Freeman, Arch. Pediat., N. Y. (1898), v. 15, p. 514. 
b Freeman, Jour. A. Med. Assn., Vol. XLIX, Nov. 23, 1907, 21, p. 1740. 
c Forster, Hyg. Rundschau, Berl. (1892), v. 2 (20), 15. Okt., p. 872. 
d Smith, Th.: J. Exper. Med., N. Y. (1899), v. 4, p. 233. 
. e Oppenheimer, Munch, med. Wchnschr. (1899), v. 46, p. 1462. 
/Hippius, Jahrb. f. Kinderh. (1905), v. 61, pp. 365-384. 
g Bitter, Ztschr. f. Hyg., Leipz. (1890), v. 8, p. 255. 
A Hesse, Ztschr. f. Hyg., Leipz. (1900), v. 34, p. 347- 
i Russell and Hastings, 17 Ann. Rep., Agric. Exper. St., Univ. Wis. (1900), p. 170. 
In view of certain differences of opinion concerning the tempera- 
ture and time of milk pasteurization, the definition still lacks com- 
pleteness. Therefore the misconceptions and confusions concerning 
the use of the term “ pasteurized milk ” have added to the prejudice 
against the process. We should protest against a word which means 
a generality and again insist upon all pasteurized milk being prop- 
erly labeled with the degree of heat , the period of time , and also with 
the date on vjhich it was subjected to the process. 
So far as we may conclude from the evidence at hand, the heat- 
ing of milk to 60° C. for twenty minutes destroys pathogenic micro- 
