POISONOUS MUSSELS. 39 



Oils mussels. It was formerly believed that the effects were 

 due to copper which the animals obtained from the bottoms 

 of vessels ; but, as Cheistison remarks, copper does not 

 produce these symptoms. Moreover, Christison made 

 analysis of the mussels which produced the symptoms ob- 

 served by Combe, and was unable to detect any copper. 

 BouCHAEDAT found copper in some poisonous mussels, but 

 he does not state the amount of the copper nor the source 

 of the animals. 



Edwaeds advanced the theory that the symptoms were 

 wholly due to idiosyncrasy in the consumer. This may be 

 true in some instances where only one or two of those par- 

 taking of the food are affected, but it certainly is not a 

 tenable hypothesis in such instances as those reported by 

 Combe and Schmidtmann, where a large number or all 

 those who partook of the food were affected. 



Coldsteeam found the livers of the Leith mussels, as 

 he thought, larger, darker, and more brittle than normal, 

 and to this diseased condition he attributed the ill effects. 



Lamoeoux, Moheing, de Bbume, Chenu, and du 

 Rondeau have supposed that the poisonous effects were 

 due to a particular species of medusse upon which the mus- 

 sels feed. De Beume found in the vomited matter of one 

 person, suffering from mussel poisoning, some medusse, and 

 he states that these are most abundant during the summer, 

 when mussels are most frequently found to be poisonous. 



The theory of Bueeow that the animal is always poison- 

 ous during the period of reproduction has been received 

 with considerable credit. However, cases of poisoning have 

 occurred at different seasons of the year. 



Ceumpe, in 1872, suggested that there is a species of 

 mussel which is in and of itself poisonous, and this species 

 is often mixed with the edible variety. Schmidtmann and 

 ViECHOW support this idea. They state that the poisonous 

 species has a brighter shell, a sweeter, more penetrating, 

 bouillon-like odor than the edible kind, also that the flesh 

 of the former is yellow aud that the water in which they 

 are cooked is bluish. Lohmbyee also champions this 

 opinion. This theory, however, is opposed b_y the majority 



