358 DIVERSIONS OF A NATURALIST 



chief causes of the disappearance not only of " scurvy " 

 but of leprosy from Europe. Leprosy is rapidly becoming 

 extinct in Norway, It still survives in a few localities, 

 and is common in several uncivilized communities in 

 remote regions, such as parts of Africa, India, China, and 

 the Pacific Islands. In an earlier chapter, p. 292, 1 have 

 referred to the disease known as " scurvy," which has 

 become so uncommon now as to have escaped thorough 

 investigation by modern pathologists. 



A few marine fish are known which are highly 

 poisonous to any and every man, even when cooked and 

 eaten in a perfectly fresh condition, and there are many 

 individuals who suffer from the " idiosyncrasy," as it is 

 called, of liability to be dangerously poisoned not only 

 by the peculiar and rare fish which are poisonous to 

 every one, but by any and every fish they may eat, or 

 by two or three common kinds only. Thus, some 

 persons are poisoned if they eat lobster or crab, or 

 oysters or mussels, but can tolerate ordinary fish. Others 

 are poisoned, without fail, by mackerel and by grey 

 mullet, but not by sole or salmon. The symptoms 

 resemble those produced in ordinary persons by the 

 " ptomaines " of putrid fish, and seem to be due to the 

 presence even in fresh fish of a kind of ptomaine which 

 some persons cannot destroy by digestion, whilst most 

 persons can do so. It is literally true that " What is 

 one man's meat is another man's poison." 



The use as a " relish " of the little fish, the anchovy 

 — allied to the sprat and the herring — preserved in salt 

 liquor in a partially decomposed state, but not under- 

 going the ordinary chemical change excited by the 

 bacteria of putrescence, is remarkable and very widely 

 spread. Anchovy sauce is made by mashing up such 

 chemically decomposed anchovies, and is one of the very 



