76 THE ECONOMIC MOLLUSCA OF ACADIA. 



As to the cause of the poisoning, we have not perfectly 

 satisfactory knowledge. In general, it appears to be due tO' 

 the exposure of the Mussels to impure waters. Some years- 

 ago a case of violent poisoning in Wilhelmshaven, in Nortb 

 Germany, which resulted in the death of several persons, led 

 to a careful investigation. It was shown that the fatal Mussels 

 had been taken from the harbor of the town, in which the 

 water, though salt, is quite stagnant, clear water entering in 

 small quantities at high tide only. Fish could not live in it, 

 and even the all-enduring eel became weak and helpless, 

 Experiments proved that all the Mussels of the still water 

 were poisonous, but that upon being removed to clear water 

 they quickly became harmless; on the other hand, perfectly 

 good Mussels, placed in the harbor, were soon very poisonous. 

 Prof. Virchow found that only the liver contains the poison, 

 and that it can be rendered harmless by cooking the animal 

 in a solution of soda. The best antidote is said to be a 

 quantity of milk. The safest way, according to this investi- 

 gator, is to remove the liver from every specimen to be eaten. 

 It is a large yellowish-brown soft body enclosing the stomach 

 on the upper side, and involved in numerous loops of the 

 intestine. The conclusion to be drawn from these facts is, 

 that Mussels from stagnant or impure waters should always 

 be avoided, and everybody ought, before eating them, to know 

 whence they came. It is thdught, too, that they may be 

 injurious when taken from docks in which cojiper-bottomed 

 ships are moored, or from harbors in which there are mineral 

 lodes exposed to the action of the w;ir,er. Several writers have 

 thought that the striped variety (yay. jjellucidus) is poisonous. 

 As mentioned above, however, these cases of poisoning are very 

 rare, and should prove no impediment to their free use, proper 

 precautions being taken to bring the supply from pure waters. 



(c) Its Use as a Fertilizer. 



When a great bed of Mussels is exposed on a flat in an 

 estuary, it is constantly catching the fine silt which the fresh' 

 water deposits when it meets the salt. The animals live their 

 short lives, die, and are buried beneath their progeny. The- 



