POISOXOUS FISHES, 
191 
Refuse' into, the water inhabited by the fishes ; (2) the de- 
composition (from long keeping or bad curing) of pre- 
served fish ; (3) the nature of the aliment consumed by the 
fishes ; (4) the use of noxious plants in order to capture the 
fish ; (5) the age of the fish ; (6) the season; (7) the com- 
mencement of alteration in the tissues of the fish after cap- 
ture ; (8) disease in the fish ; (9) the effect of copper-beds 
at the bottom of the sea. In "regard to cases (1) and (2), 
M. Dumeril appears to admit these causes, but only as 
operating in a moderate number of cases. (3) seems to be 
very doubtful, especially as to the feeding of the fishes upon 
coral and the fruit of the manchineel, which does not seem 
to have been verified. As to (4), H. Dumeril considers 
that a great number of the plants employed for poisoning 
fishes do nof thereby cause any bad effects upon man, 
whilst others are admittedly hurtful. A note is appended 
to the paper, giving the names of the nocuous and inno- 
cuous species of plants. (5) seems to be deserving of con- 
sideration, being admitted in practice with respect to seve- 
ral species of fish ; (6) season has undoubtedly some influ- 
ence, and many fish appear to bo baneful at the period of 
spawning; their oval being especially hurtful. It is under 
the head of (7) that our author seems disposed to place* 
perhaps, the majority of accidents due to the eating of fish. 
He admits the probable efficacy of the test of a piece of 
silver in respect of this cause, the liberation of sulphuretted 
hydrogen causing the blackening of the metal. In respect 
of (8) it is suggested that a condition of disease may some- 
times alter the natural qualities of the fish. (9) The au- 
thor attaches no importance whatever to the influence of 
copper-beds. 
