FlTCliETr.--Physio[u(/ical Action of Tulin. 



313 



symptoms at the end of five hours, and died in 25J hours ; a second showed 

 symptoms at the end of six hours and a quarter, and died at twenty-eight 

 hours ; and the third showed slight symptoms at the end of eight hours, 

 and recovered. The fluid was filtered, and three fresh fishes introduced, 

 and of these one died within sixteen hours, one at 22J hours, and one re- 

 covered (Exp. 97). 



A third experiment (Exp. Ill) was made with U-()05 per cent, tutin in the 

 same way. Symptoms appeared in two of the fish at five hours and a third ; 

 these died at eight hours and a sixth and nine hours and a sixth respectively. 

 The third showed symptoms at six hours and two-thirds, and died at 

 13f hours. Usually fish live in a 0-005-per-cent. solution of tutin for an 

 average of seventeen hours. 



To summarise the results of these three experiments : Twelve fish were 

 subjected to the influence of hydrolysed tutin (0-0035 per cent, to 0-005 per 

 cent.). Of these, ten died at an average period of fourteen hours ; the 

 other two showed symptoms, but recovered. In the corresponding control 

 solutions, of the twelve fish, nine died at an average period of 16-9 hours 

 two showed symptoms, and recovered ; and one showed no symptoms 

 It would seem to follow that In^drolysed tutin is more toxic than tutin itself 

 but the rise in toxicity is not great, and in marked contrast to the action 

 which takes place in dilute alkali at corresponding strength. 



(r/.) Action of Alkalis on Tulin. 



Attention having been arrested by the fact that animals poisoned by 

 tutin are frequently reduced to a state of coma, which may possibly con- 

 tribute towards a fatal termination, the use of alkahs as a remedial agent 

 suggested itself. Hughes had found that lime destroyed the activity of the 

 tutu poison, and Easterfield and Aston were unable to recover tutin after 

 a solution treated with lime had been evaporated to dryness. 



Table VII. 

 Effect of Alkali on the Toxicity of Tutin. 



The experiments were done in the same way as in the case of HCl : 10 c.c. 

 of a 0-5-per-cent. solution of tutin was rendered alkaline with the solution 



