tracted with hot alcohol, and the alcoholic extract concentrated, neutralized, and taken up with water to form a clear liquid in some cases, in others an emulsion.

Blood.—Since the practice of bleeding is universally recognized as valuable in the treatment of stock poisoned by tutu, my attention was specially drawn to this tissue. In bleeding “tutued” sheep it is a common practice to slit a vein near the eye—the blood flows down on the face, and much of it is said to be swallowed. This led me to try whether fresh blood has any influence on the toxicity of tutin. Exp. 225 shows that it has little, if any, effect. The other experiments recorded here had as their object the discovery of tutin in the blood; and the results show that shortly after the administration of large doses of tutin the blood contains somo poison—either tutin itself in traces or some other toxic body arising from it or resulting from its action. The experiments in support of this are the following:–

Exp. No. 234: Rabbit, weight 2,010 grm., received 10 mlgrm. tutin intravenously. Respiration immediately became quickened; seven minutes after injection the animal began to show muscular symptoms, and at eight minutes a typical convulsion broke out. Twenty minutes after the in-jection, and when nearly dead, it was killed by bleeding; the blood was defibrinated, and within twenty minutes 10 c.c. of it was injected in two portions into the ear-vein of a rabbit (No. 235) weighing 1,350 grm. The animal became dazed and sleepy-looking; it sat with its eyeballs rolled up under the half-closed lids, and the respiration-rate was markedly increased. It also licked its lips repeatedly as if salivating, but within an hour it seemed to have completely recovered. These symptoms point to the presence of some tutin or an allied toxic body in the blood. If all the tutin were present in the blood as such the dose would have been 1 mlgrm., and the animal would have shown much more decided symptoms. The residue of the blood of the first rabbit was evaporated to dryness; it then weighed 7·2 grm., and therefore represented about 35 c.c. of blood = one-third of the total blood of the animal. The dried residue was treated with alcohol, and the alcoholic extract taken up with water as already described. The whole quantity was given by mouth to a kitten (No. 237). It developed some twitching of the ears, licking of its lips, and swallowing movements, &c., but recovered completely. The symptoms here are suggestive of small amounts of tutin in the blood; and on calculating the percentage present, if the tutin were uniformly distributed throughout the body, one may safely conclude that the blood had more than its due share of the poison, while, as shown above, the blood did not contain all the poison.

Exp. No. 232: Rabbit, weight 1,588 grm., received hypodermically 1·5 c.c. of 0·5 per cent. tutin = 7·5 mlgrm. The animal had severe symptoms, and was killed half an hour after the dose was administered. The brain and cord weighed 11 grm. The blood and washings of blood-vessels yielded 9·8 grm. dried material; it was calculated, therefore, that the amount of blood obtained = 43 c.c. = more than half the total blood.

Both tissues were acidified with HC1 and evaporated to dryness, then both were extracted with absolute alcohol and the extract dissolved in water after removing the alcohol.

The whole of the extract of brain and cord, measuring 3 c.c., was injected into the peritoneum of a rabbit weighing 673 grm., but no symptoms of any kind followed.

The watery extract of blood obtained in the same way also measured 3 c.c. Half of it was injected intravenously into a small rabbit (weight, 671 grm.). Before the injection was finished it jerked its head backwards, and when released fell over on its back, clawed the air in a convulsive manner, and was dead in a few seconds.

The remaining half of the extract was given hypodermically to another small rabbit. During the injection the animal writhed as if in pain, later on the latter half of the body became paralysed, the respiration became very feeble, but in about half an hour it had completely recovered.

Exp. No. 233: The blood of a normal rabbit, measuring about 30 grm., was treated in an exactly similar way to that of No. 232, and the final watery extract injected into the small rabbit that had survived (vide supra). No symptoms followed, and there is little doubt but that the blood in this case (232) contained some toxic body, although the symptoms produced were not those of tutin.

Other experiments bearing on this part of the subject are detailed in the protocols of experiments 199, 229, and 244; but I consider the results less conclusive here, because frogs frequently die when injected with foreign material, and the blood, at least in cats, may give reduction without being hydrolyzed, while in Exp. 244 the blood of a tutinized cat failed to give the reduction test.

These results indicate that the beneficial effects of bleeding can hardly be ascribed to the removal of the poison in the shed blood, for the tutin absorbed from ingested tutu is not likely to be present in such high concentration as in these experiments, and yet the blood in these cases had comparatively feeble toxic power although the quantities used were relatively large—certainly larger relatively than would occur in bleeding as usually practised on sheep.

Brain.—From Dr. Ford's statements one might be led to believe that practically all of a moderate dose of tutin becomes concentrated in the brain of the animal. As already stated, I was unable to confirm this by the chemical test, and the brological test, with one exception, also gave negative results. Thus in the experiment described above (No. 232) the hydrolyzed brain of the rabbit produced no effect.

In Exp. 229 the extract of brain gave no reduction after hydrolysis, but some reduction was obtained with the extract of foetal brains. This latter point requires further investigation; a reducing body may be normally present. The result of injection of the hydrolyzed brain extract into a frog is inconclusive, because the control frog, in which the extract was treated with KOH to destroy the suspected tutin, also died.

In Exp. 240 a rabbit weighing 1,350 grm. received 10 mlgrm. tutin intravenously. The brain, with the spinal cord, weighing 10·3 grm., was extracted with alcohol, and the extract was dissolved in water. One-third of this solution was injected into a cat without effect. The material used here was not hydrolyzed, and the absence of symptoms corresponds to Ford's results. Another portion of the extract of brain was tested for reduction after hydrolysis, without result.

Exp. 244 similarly gave a negative result by the reduction method. The only experiment which gave some indication that the brain may contain a toxic body was No. 236. In this case a young cat, weighing 760 grm., received the emulsified brain of rabbit 234, which had been poisoned with 10 mlgrm. of tutin. After about an hour it showed some twitching of the ears, licking of its lips, swallowing movements, deliberate