314 Transactio?is. 



used in the foregoing experiments to neutralise the weak liydrochloric acid. 

 The alkaUnitv used was equivalent to 0-2 per cent. HC'l. or a little over 

 0-2 per cent." It was found (Exps. 96, 99. 101, 102. 109, 112) that tutin 

 solution kept at 37° C. in the presence of that amount of alkali completely 

 lost its toxic power. In the first experiment the time allowed for the alkali 

 to act on the tutin was one hour, and the three fish that were subjected 

 to the action of the solution were unaffected after thirty hours. The fluid 

 was filtered and three other fish introduced for twenty-seven hours, but 

 without effect. 



In other experiments the time allowed for the alkali to act upon the 

 tutin was shortened successively to forty minutes, twenty minutes, ten 

 minutes, and five minutes, but the result was the same in each case — the 

 tutin had completely lost its toxic power. 



In this connection the following experiment on a cat may be cited 

 (Exp. 113) : 8 c.c. of a 0-5-per-cent. solution tutin was treated with 1 gram 

 of lime [CalOHg)] for one hour at 37° C, and thereafter for one day at 

 room-temperature. The lime was removed by passing CO2 and filtering, 

 and the fluid was evaporated to about 2 c.c, and injected under the skin 

 of a cat weighing 2-4 kilograms. It displayed no symptoms, and remained 

 well. 



(c.) Influence of " Surviving '' Organs on Tutin. 



In considering the explanation of the relative immunity of birds to tutin 

 poisoning by oral administration, it was suggested {vide ante) that the inter- 

 position of the liver in the usual path of absorption in mammals might 

 account for some increase in the toxicity of the tutin in their case. To test 

 the influence of the liver-substance on tutin, an experiment was carried out 

 as foUoW'S : A rabbit was killed by chloroform, a canula was tied into the 

 aorta, and the blood-vessels washed free of blood by a stream of warm saUne. 

 The liver and kidneys were rapidly excised, 9 grams of each weighed out, 

 minced, and bruised rapidly in a \varm mortar. To each mass 10 c.c. of a 

 0-5-per-cent. solution of tutin in normal saline was added. The mixtures, 

 in small wide beakers, w^ere placed in the oven at 37° C. for one hour. An 

 equal volume of absolute alcohol was then added, to stop further action. 

 The mixtures were then evaporated on a water bath, and kept there for some 

 hours to coagulate the proteids. A watery extract of each was then made, 

 filtered, and made up to 1,000 c.c. with tap-water. Three minnows were 

 placed in each of these solutions, and the results were as follows : — 



Liver and Tutin (Exp. 103) : One fish showed symptoms at two hours 

 and a third, and died in five hours and a half ; one showed symptoms in two 

 hours and a third, and died in six hours ; and one showed symptoms in four 

 hours and a half, and died in seven hours and three-quarters. 



Kidney and Tutin (Exp. 104) : One showed symptoms at an hour and 

 a half, and died in four hours and a half ; one showed symptoms at four 

 hours and a half, and died in seven hours and three-quarters ; and one 

 showed svmptoms in four hours and a half, and died in twenty-seven hours. 



The course of events in the latter case is just similar to that of a 0-005- 

 per-cent. solution of tutin, so that we may suppose that here the tissue had 

 no effect on the tutin ; but, on the other hand, it is difficult to avoid thinking 

 that the liver-substance increased the toxicity of the tutin, 



6. Action on Insects. 

 Insects are susceptible to the action of the poison. Weak solutions 

 (0-1 per cent.) have no influence. A number of flies lived in perfect health 



