From the results of the experiments of this series it appears that 0.15 gram caffein per kilo may be fatal within a few hours after its administration, even if the drug is mixed with a moderate amount of meat. Experiments 87 and 92 show, however, that this amount may be borne by some individuals without any serious consequences, as the cats were under observation for some time after they received caffein, and no untoward symptoms were noticed in either of them during this time. It may be remarked that cat No. 92 vomited shortly after it received caffein. It is practically certain, therefore, that this amount of caffein in proportion to the weight of the animal will in the great majority of cases prove fatal, and perhaps in a smaller percentage of individuals it is surely toxic if it does not escape absorption. Smaller doses may cause irritability in some individuals, but symptoms referable to nervous symptoms of muscles were absent, as in experiments Nos. 93 and 100. The minimum fatal dose of caffein for the cat when given by mouth is, therefore, 0.15 gram per kilo. TABLE 9.--_Subcutaneous injection; cats._ SERIES A. -------+--------+---------+-----------------------+------------------- Number.| Weight.| Caffein | Symptoms. | Duration of life. | |per kilo.| | -------+--------+---------+-----------------------+------------------- |_Grams._| _Gram._ | | 4 | 1,440 | 0.30 | 65 minutes | Over 29 hours. 5 | 1,396 | .30 | | About 2 hours. -------+--------+---------+-----------------------+------------------- SERIES B. -------+--------+---------+-----------------------+------------------- 3 | 2,854 | 0.25 | | 30 minutes. 6 | 1,645 | .243 | Few minutes | 1 hour 30 minutes. 8 | 1,735 | .25 | 30 minutes. | 1 hour. 9 | 1,960 | .25 | 1 hour | 1 hour 45 minutes. 12 | 1,185 | .20 | 3 hours | Less than 18 hours. 14 | 1,855 | .20 | 1 hour 20 minutes | Do. 15 | 2,145 | .20 | 40 minutes. | Do. 19 | 1,100 | .236 | 15 minutes | Do. 20 | 790 | .25 | | 4 hours 30 minutes. -------+--------+---------+-----------------------+-------------------- SERIES C. -------+--------+---------+-----------------------+------------------- 24 | 1,300 | 0.153 | 1 hour | Survived. 17 | 2,620 | .15 | 15 minutes | Do. 23 | 1,645 | .15 | | 1 hour 10 minutes. 7 | 1,285 | .155 | 20 minutes | 1 hour. 9 | 2,285 | .14 | | 65 minutes. -------+--------+---------+-----------------------+------------------- SERIES D.