----+--------+-------+----------+-----------+----------+------------- 307| 1,175 | 0.136 | 5 hours |6 hours, | Lumbar |Gray female. | | | | 20 minutes| | 306| 1,860 | .134 | 3 hours |4 hours | do. | Do. 181| 1,230 | .130 | 4 hours |5 hours | do. |Gray. ----+--------+-------+----------+-----------+----------+------------- SERIES C. ----+--------+-------+----------+-----------+----------+------------- 425| 1,520 | 0.131 | 1 hour |Survived | Lumbar |Gray. 426| 1,405 | .142 |30 minutes| do. | do. |Gray female. 427| 1,830 | .153 |50 minutes| do. | do. | Do. 453| 1,160 | .200 |30 minutes|Less than | do. |Gray male. | | | | 20 hours | | 455| 1,185 | .200 | do. |Survived | do. |Gray female. 428| 1,650 | .180 | |Less than | do. |Gray male. | | | | 20 hours | | 429| 1,340 | .200 | | do. | do. | Do. ----+--------+-------+----------+-----------+----------+------------- SERIES D. ----+--------+-------+----------+-----------+----------+------------- 577| 1,380 | 0.200 |10 minutes|Less than | Gluteal |Gray male. | | | | 18 hours | | 578| 1,670 | .210 | do. | do. | do. | Do. 579| 1,490 | .200 |15 minutes|Survived | do. |White and | | | | | | gray male. 580| 1,510 | .200 | | do. | Lumbar |Gray male. 581| 1,680 | .200 |15 minutes|50 minutes | do. | Do. 582| 1,870 | .192 |45 minutes|Survived | do. | Do. ----+--------+-------+----------+-----------+----------+------------- Examination of Table 4 shows that 14 rabbits received from 180 to 210 mg caffein per kilo. The appearance of symptoms in these rabbits varied considerably. In some increased reflexes could be noticed in 10 to 15 minutes after the injection of caffein; in others it was delayed 2 or 3 hours. It might be added that the onset of symptoms occurred in many cases very soon after the administration of the drug--on an average about 10 to 30 minutes after the drug was injected. After smaller doses were administered by injection into the lumbar muscles the appearance of symptoms was delayed several hours in some cases. The duration of life in these 14 rabbits varied considerably. Eight of them died within 1 to 20 hours; six survived. About 0.2 gram caffein per kilo may be regarded as the minimum fatal dose, while the minimum toxic dose is somewhere between 130 and 150 mg per kilo. INTRAVENOUS INJECTION.