332 Transactions. 



diminislied by the^absorption of the CO 2, wliich no doubt forms part of the 

 mixture of gases present, so the distension that so frequently occurs in these 

 cases would be diminished. 



The comatose condition which forms part of the symptoms of tutin 

 poisoning suggested the possibility of some form of acid poisoning being 

 present, and, if this be so, the injection of alkalis should prove of benefit. 

 Sodium-carbonate was tried intravenously in one of the blood-pressure 

 experiments, but no apparent effect was observed. In another case sodium- 

 carbonate was injected into the rectum of a rabbit that seemed likely to die- 

 of tutin poisoning, but here also it was ineffective. So that for the present 

 one can only say that alkali would render unabsorbed tutin non-toxic. 



19. General Summary. 



1. Investigations made on the action of the pure principle tutin 

 (C17H20O7) confirmed the results of previous observers that it is in itself 

 sufiicient to account for the main bulk, if not the whole, of the symptoms 

 of poisoning by the tutu plant. 



2. These symptoms, as they occur in cats, have been fully described, 

 and the differences which appear in other animals noted. 



3. Tutin, or its metabolic products, acts mainly on nerve-cells, producing 

 first increased excitability and then exhaustion. It specially affects the 

 cells of the respiratory centre, causing increased rate and depth of respiration. 



4. Death may occur during the phase of increased excitability (asphyxia 

 during convulsions) or in the phase of exhaustion. Various reflex acts — 

 vomiting, defalcation, micturition^ — may occur during the stage of increased 

 excitability. A comatose condition, possibly due to exhaustion of the cells 

 of the cerebral cortex, is a marked feature in proportion to the strength of 

 the dose. It deepens as death approaches. Small haemorrhages 'into and 

 congestion of the grey matter of the brain and cord are marked features in 

 fatal cases. The Nissl granules seem unchanged when death occurs in a 

 short time. 



5. In strong solutions tutin has a slight deleterious action on tissues less 

 highly specialised than nerve tissue — e.g., ciUated epithelium and muscle. It 

 retards the growth of some forms of bacteria, and injuriously affects para- 

 moecia and other low forms of life in relatively strong solutions. 



6. The symptoms of poisoning by tutin are in a general way similar in 

 widely different forms of life (flies, pigeons, cats, (fee), and can all be referred 

 to an action on nerve-cells. 



7. The minimum lethal dose in milHgrams per kilo of body-weight for 

 different classes of animals is as follows : — 



8. The effects on the various systems can all be referred to the influence- 

 on their nerve mechanisms — e.g. : Alimentary system, salivation, vomiting 

 (on hypodermic injection). The circulatory system is not injuriously afl'ectedi 



