160 M. A. Dumeril on Venomous Fishes. 



1. The mackerel taken at St, Helena is, according to Quar- 

 rier, constantly poisonous if kept for a single night; if pre- 

 pared, however, on the same day on which it is caught, it is 

 not so. 



2. The inhabitants of the Antilles say that the Bonito should 

 be dressed for the table as soon as it is taken from the water*. 



3. The Chinese eat the Tetraodon ocellatus, one of their best 

 fishes, as soon as it is capturedf. 



4. The instances of poisoning belong almost exclusively to 

 countries where the temperature is very high, and more espe- 

 cially to the great heats of the year — that is to say, when de- 

 composition is most rapid. 



5. Finally, it is to a phenomenon of this sort that we must 

 attribute the change of colour which takes place on a silver 

 spoon plunged into the vessel in which the fish is being cooked, 

 black sulphuret of silver being formed as a consequence of the 

 liberation of sulphuretted hydrogen, which is a sure indication 

 of a decay of tissue. 



VIII. 



In fishes that are thus baneful, it is perhaps sometimes a 

 condition of disease which alters the natural qualities. 



IX. 



I pass over in silence the role attributed to copperas-beds 

 in certain marine bottoms. In the already cited memoir by 

 M. Moreau de Jonnes (pp. 14—19) there are some remarks of 

 sufficient weight, tending to demonstrate the impossibility of 

 accepting the hypotheses which have been put forward on this 

 subject. 



In conclusion, it is evidently not proper to adopt any one of 



* The necessity of eating this fish without delay has often been remarked; 

 but an instance of the danger incurred by neglecting to do so is given in a 

 memoir by M. Morvan de Lannilis ( Journ. de Chim. Med., Pharni., Toxicol., 

 redige par A. Chevallier, 4'^ serie, t. iii. p. 719, 1857), vvho relates that 

 five persons, having ex])erienced no ill effects after eating, on board the 

 corvette ' Corneline,' at Teueriffe, some Bonitos freshly caught, suffered 

 severely for an hour or tv\o on the following day for having breakfasted on 

 some of those reserved over night. M. Guyou witnessed at Martinique, in 

 1822, a case of poisoning which, though not mortal, disturbed the health 

 of an entire company of soldiers for several hours most fearfully. The 

 repast, which took ])lace at 3 o'clock p.m., consisted of Bonitos bought 

 in the afternoon of the preceding day, and supposed to have been taken 

 in the morning of that day. Thus the thirty hours since the fish were 

 first captured sufficed for a most considerable alteration in their condi- 

 tion. 



t According to Forster, this is the fish eaten by the Ja))anese when they 

 wish to commit suicide. 



