SERIES A.
Number of pig. Weight.Caffein per kiloAppearance of symptoms inDuration of life. Diet. Month. Remarks.
Grams. Mg.
41 700 0.1302 hours 15 minutes22 hoursOatsAprilMale.
49 370 .1352 hoursSurvived do. do. Do.
47 550 .1271 hour do. do.MarchFemale.
50 290 .1382 hours do. do.April Do.
SERIES B.
51 415 0.144 NoneSurvivedOatsOctoberFemale.
52 450 .155 do. do. do. do.Male.
53 490 .163 do. do. do. do. Do.
SERIES C.
59 375 0.200 15 minutesSurvivedOatsOctoberGray and white.
58 380 .200 10 minutes do. do. do.
56 440 .200 15 minutes14 days do. do.Male.
55 690 .188 1 hour3 hours 30 minutes do. do. Do.
SERIES D.
67 330 0.240 5 minutes30 minutesOatsOctoberMale.
63 340 .235Survived do. do. Do.
64 305 .250 25 minutes4 hours 40 minutes do. do.Female.
SERIES A.
Number of pig. Weight.Caffein per kiloAppearance of symptoms in
Grams. Mg.
41 700 0.1302 hours 15 minutes
49 370 .1352 hours
47 550 .1271 hour
50 290 .1382 hours
Number of pig.Duration of life. Diet. Month. Remarks.
4122 hoursOatsAprilMale.
49Survived do. do. Do.
47 do. do.MarchFemale.
50 do. do.April Do.
SERIES B.
Number of pig. Weight.Caffein per kiloAppearance of symptoms in
Grams. Mg.
51 415 0.144 None
52 450 .155 do.
53 490 .163 do.
Number of pig.Duration of life. Diet. Month. Remarks.
51SurvivedOatsOctoberFemale.
52 do. do. do.Male.
53 do. do. do. Do.
SERIES C.
Number of pig. Weight.Caffein per kiloAppearance of symptoms in
Grams. Mg.
59 375 0.200 15 minutes
58 380 .200 10 minutes
56 440 .200 15 minutes
55 690 .188 1 hour
Number of pig.Duration of life. Diet. Month. Remarks.
59SurvivedOatsOctoberGray and white.
58 do. do. do.
SERIES D.
5614 days do. do.Male.
553 hours 30 minutes do. do. Do.
SERIES D.
Number of pig. Weight.Caffein per kiloAppearance of symptoms in
Grams. Mg.
67 330 0.240 5 minutes
63 340 .235
64 305 .250 25 minutes
Number of pig.Duration of life. Diet. Month. Remarks.
6730 minutesOatsOctoberMale.
63Survived do. do. Do.
644 hours 40 minutes do. do.Female.

Table 8.—Caffein by mouth; guinea pigs.

SERIES A.
Number of pig. Weight.Caffein per kiloAppearance of symptoms in
Grams. Mg.
129 855 0.28040 minutes
130 800 .30030 minutes
131 860 .28020 minutes
135 955 .1501 hour 50 minutes
134 740 .1603 hours
1137 925 .15050 minutes
1136 1,000 .150 do.
126 980 .20020 minutes
127 760 .2001 hour
128 1,075 .2003 hours
Number of pig.Duration of life. Diet. Month. Remarks.
129Less than 8 hoursHay and oatsJuneMale.
130Less than 18 hours do. do. Do.
131 do. do. do. Do.
1356 days do. do. Do.
1344 days do. do. Do.
11376 days do. do. Do.
1136Survived do. do. Do.
12627 hours do. do. Do.
12728 hours do. do. Do.
1287 hours do. do. Do.

1 Subcutaneous injection for comparison.

SERIES A.
Number of pig. Weight.Caffein per kiloAppearance of symptoms inDuration of life. Diet. Month. Remarks.
Grams. Mg.
129 855 0.28040 minutesLess than 8 hoursHay and oatsJuneMale.
130 800 .30030 minutesLess than 18 hours do. do. Do.
131 860 .28020 minutes do. do. do. Do.
135 955 .1501 hour 50 minutes6 days do. do. Do.
134 740 .1603 hours4 days do. do. Do.
1137 925 .15050 minutes6 days do. do. Do.
1136 1,000 .150 do.Survived do. do. Do.
126 980 .20020 minutes27 hours do. do. Do.
127 760 .2001 hour28 hours do. do. Do.
128 1,075 .2003 hours7 hours do. do. Do.

1 Subcutaneous injection for comparison.

SUMMARY.

A survey of the results obtained in experiments on guinea pigs shows that the mode of introduction of caffein exerts but little influence on its toxicity. On careful analysis it will be observed that the rate of absorption after the administration of caffein by mouth, subcutaneously, or intraperitoneally is about the same for the time of appearance of symptoms. The persistence of the symptoms of caffein intoxication observed in these experiments for 24 hours after administration points to slow elimination, which may be expected, owing to the fact that the guinea pigs passed but little urine and caffein is not diuretic for these animals. The prolonged presence of caffein in the body probably exerts a harmful influence or after effect, which may account for the delayed death of some animals many days after a single dose of caffein was given. Among the factors which undoubtedly influence toxicity, season should be considered, while the presence of a diseased condition undoubtedly tends to decrease the resistance of the guinea pig to caffein. Diet was without any influence on the toxicity of the single dose of caffein.

EXPERIMENTS ON CATS.