ON POISONOUS FISHES AND FISH-POISONS. 301 



in organisation, whether saline or earthy, animal or vegetable, are combina- 

 tions always so arranged by the powers of life as to be diffused. They are 

 never so concentrated as to assume the crystalline form, except when in a 

 state of excretion. As a general principle, crystallisation determines the 

 incompatibility of the matter with the life of the structure in which it 

 occurs* 



The liver of fishes, in performing its function of separating impurities 

 from the blood, and of secreting fluids necessary to digestion, must do all 

 the increased depuratory work attendant on the absence of lungs. Exha- 

 lations from animals living in aeriform fluids are properly excretions. From 

 animals living in aqueous fluids, excretory action must be much modified, 

 and in fishes it exists only by that energy of " reduction " in which the 

 albuminous matters of the chyle evolve gases by the " processes of comple- 

 tion." f (Prout's Bridgwater Treatise.) In reptiles the liver is large, in con- 

 sequence of the low degree of respiration of that class of vertebrate animals ; 

 for the same reason it is large in fishes, and very large among the inverte- 

 brata. In fishes the gall-bladder is observed for the first time in the animal 

 series, as we ascend from the invertebrate to the vertebrate classes, but it is 

 not constant in its existence among them. It is absent in many genera, and 

 it is then substituted by a peculiar economy of efferent tubes. The com- 

 pensatory energy of the liver in this class of organic beings must render 

 it vastly congestive. We know that fish-liver contains an enormous 

 quantity of oil, that fish-oil is an important article of commerce, and 

 fish-liver oil is a valuable medicine ; but we know, beside, that these oils 

 in a corrupt state are active poisons. Hence we may infer that the liver is 

 a great operator in the injury done by deleterious fishes ; and if we but 

 knew all the genera in which the gall-bladder is wanting, we might arrive 

 at some rule for estimating the possible development of those prejudicial 

 fluids that mingle from the liver with fish-flesh in cooking. 



Before adverting to the circumstances under which tunny fish, when 

 becoming unwholesome, is condemned by the police in the market of Venice, 

 it is necessary to remark some peculiarities in the organisation of the 



* I have no experience of the manifestation of kreatine or flesh-crystals in fishes 

 either occasionally or permanently poisonous ; but the ordinary chemical property of 

 living structures as laid down by Dr Prout, in the Bridgwater Treatise, book hi., 

 ch. i. on the "Chemistry of Organisation," is, that "the essential elements are 

 hindered from assuming a regular crystallised form. The incidental matters entering 

 into the composition of a living body apparently furnish to the organic agent new 

 powers— which powers the organic agent has been endowed with the ability to control 

 and direct, in any manner that, from the exigencies of the living organised being, may 

 become requisite." Easpail, in his ' Chimie Organique," section 1&78, says, "Jamais 

 je n'ai apenju de crystaux dans le sein d'une cellule vivante, et d' accroissement." 



+ II y a des poissons," says M. Ehrmann, illustrating excretory modification iu 

 nutrition, "qui avalent l'air atmospherique et en convertissent l'oxigene en acide car- 

 bonique, en la faisant passer au travers de leur intestins. Tel est le cobitis,— il se 

 fait & la peau et sous les ecailles une transmutation semblable." (Cuvier, Hist. 

 Natur. des Poissons, vol. i., liv. ii., ch. vii.) 



