Jan.31,1916 
Effects of Refrigeration on Trichinella spiralis 
837 
Table II .—Summary of results of refrigeration experiments with larvae of Trichinella 
spiralis exposed to various temperatures 
Exposure to about 
is 0 F. 
Exposure to about 
io° F. 
Exposure to about 
5° F. 
Exposure to about 
o° F. 
Experiment No. 
Number of days. 
Examination. 
Feeding tests. 
Experiment No. 
Number of days. 
Examination. 
Feeding tests. 
Experiment No. 
Number of days. 
Examination. 
Feeding tests. 
Experiment No. 
Number of days. 
i 
’i 
► 
w 
Feeding tests. 
3 
2 
+ 
50 
(a) 
+ 
49 
( b ) 
4 
( c ) 
_ 
7 
S 
4- 
.... 
35 
5 
+ 
+ 
2 
(a) 
— 
— 
5 
m 
— 
17 
5 
+ 
— 
11 
6 
+ 
+ 
*l6 
5 
— 
— 
6 
(a) 
— 
18 
5 
+ 
— 
36 
6 
+ 
— 
19 
5 
— 
— 
8 
2 
4 
.... 
20 
5 
4- 
— 
56 
6 
+ 
+ 
42 
5 
+ 
+ 
9 
3 
+ 
— 
21a 
6 
.... 
— 
37 
7 
+ 
— 
21 
6 
.... 
— 
10 
5 
23 
7 
+ 
+ 
Si 
7 
+ 
+ 
43 
6 
— 
— 
13 
5 
— 
24 
9 
+ 
+ 
57 
7 
+ 
44 
7 
+ 
— 
67 
5 
4 
4- 
25 
10 
+ 
— 
38 
8 
— 
.... 
45 
8 
— 
.... 
1 
6 
— 
22 
10 
+ 
— 
52 
8 
.... 
+ 
46 
9 
+ 
— 
12 
6 
4- 
— 
22a 
10 
.... 
— 
58 
8 
+ 
+ 
47 
10 
— 
' — 
14 
8 
— 
22b 
10 
.... 
— 
39 
9 
+ 
— 
91 
10 
— 
— 
68 
10 
+ 
4- 
ns 
10 
+ 
4- 
S3 
9 
+ 
4- 
48 
11 
— 
— 
69 
10 
— 
26 
11 
4- 
+ 
59 
9 
.... 
+ 
92 
11 
— 
__ 
70 
14 
4- 
— 
116 
11 
+ 
+ 
40 
10 
+ 
— 
93 
13 
— 
— 
72 
15 
— 
15 
12 
— 
— 
54 
10 
4- 
4- 
88 
14 
+ 
— 
77 
15 
— 
27 
12 
+ 
— 
60 
10 
.... 
+ 
94 
14 
+ 
— 
80 
15 
— 
28 
13 
+ 
_ 
103 
10 
+ 
+ 
95 
15 
— 
— 
82 
IS 
— 
117 
13 
+ 
+ 
41 
n 
.... 
— 
96 
16 
— 
— 
84 
15 
— 
29 
14 
.... 
+ 
55 
11 
+ 
+ 
97 
17 
— 
— 
86 
15 
— 
90 
14 
+ 
+ 
61 
11 
.... 
+ 
98 
18 
+ 
— 
74 
18 
— 
118 
14 
+ 
+ 
104 
11 
+ 
+ 
99 
20 
— 
— 
75 
20 
— 
119 
IS 
+ 
+ 
62 
12 
+ 
+ 
loo 
21 
.... 
— 
79 
23 
— 
30 
16 
4- 
+ 
63 
13 
4- 
4 - 
IOI 
22 
— 
— 
120 
16 
+ 
+ 
i°5 
13 
+ 
+ 
102 
23 
— 
— 
78 
17 
+ 
— 
64 
14 
4- 
— 
81 
17 
+ 
— 
89 
14 
+ 
— 
83 
17 
+ 
— 
106 
14 
+ 
+ 
121 
17 
+ 
+ 
73 
15 
4- 
— 
31 
18 
+ 
+ 
107 
15 
4- 
— 
85 
18 
4- 
— 
108 
16 
+ 
— 
87 
18 
4- 
— 
7i 
17 
+ 
+ 
122 
18 
4- 
+ 
109 
17 
+ 
— 
123 
20 
+ 
+ 
no 
18 
+ 
— 
32 
21 
+ 
— 
65 
19 
+ 
+ 
124 
21 
— 
65a 
19 
+ 
*r 
33 
22 
+ 
— 
66 
19 
4- 
— 
125 
22 
+ 
— 
76 
20 
4- 
— 
126 
23 
+ 
+ 
in 
20 
4- 
— 
34 
24 
.... 
*— 
112 
21 
.... 
— 
113 
22 
+ 
— 
114 
23 
4- 
— 
127 
57 
+ 
a 30 minutes. & 25 minutes. c 10 minutes. d 20 minutes. 
RESULTS OF EXPERIMENTS 
effects of various low temperatures upon the vitality of trichina 
In only one instance out of 34 experiments in which trichinous meat 
was exposed to temperatures of about 15 0 F. for periods ranging from 
2 to 23 days were all of the trichinae upon examination found to be inact¬ 
ive (experiment 15, 12 days). In most instances, although some were 
found to be inactive, a large proportion were commonly found to be 
active, not rarely as high as 98 to 100 per cent. In one case, even after 
18 days' exposure (experiment 31), over 99 per cent of the trichinae were 
found active on examination, and in another case after 22 days (experi¬ 
ment 33) 84 per cent were active. 
