56 SolavMcex [ch. 



haulm, but in the flowers and fruits, and in the peel of the tubers. 

 Solanidine also occurs ready-formed in the young sprouts of potatoes to 

 the extent of 1-5 per cent. (Allen). In the case of the soldiers poisoned in 

 Berlin analysis demonstrated the presence of Solanine to the extent of 

 0-038 per cent, in boiled tubers and 0-024 per cent, in raw tubers, and 

 on an average every man who fell iU had 0-3 gramme of the alkaloid, a 

 sufficient quantity to produce toxic results. Esser (1910) states that in 

 midsummer the haulm contains 0-0925 per cent, of Solanine but late 

 in summer only 0-0374 per cent. In the tubers the alkaloid occurs in 

 the inner layers of the peel to the extent of 0-0124 per cent., red or pink 

 varieties containing rather more than yellow sorts. The same authority 

 says that damp soils tend to a higher percentage of Solanine than dry 

 soils^, and that nitrogenous manuring as compared with potash tends 

 to an increase of Solanine. In fresh spring shoots 1-5 per cent, of the 

 alkaloid has been found, and the percentage is especially high in tubers 

 which have been "greened" by long exposure to light. As already 

 stated it is the greened tubers which appear to be the chief cause of 

 accidents. Tubers with young shoots are richer in poisonous alkaloids 

 than those which have not yet been sprouted; such tubers when fed 

 raw to Stock may on occasion induce poisoning, unless fed only in small 

 quantities. 



Writing in 1887 Comevin remarked that Solanine, though neither 

 very active nor very abundant in Potatoes, nevertheless causes accidents, 

 as it is cumulative, or, to be more exact, is eliminated slowly. 



Symptoms. In poisoning by potato haulm, Comevin records con- 

 stipation, loss of appetite, rise in temperature, accelerated circulation, 

 normal respiration, salivation, tumefaction of eyelids, eyes watery, con- 

 junctivae injected, and hair erect. The skin is covered with scabs which 

 exude matter, the skin being cracked. These scabs are found especially 

 on the scrotum of male cattle and the udder of female cattle, but also 

 in the caudal region and roimd the anus. An examination of the mouth 

 shows places on the upper jaw which are devoid of mucus and are 

 purulent at the centre, the mucus round the edges being swollen. The 

 posterior members are similarly but not so badly affected. Movement 

 of these members seems to cause the animal much pain. Defecation 

 is frequent, the faeces being hquid and dark in colour. The animals are 

 recumbent for a considerable time with the posterior members stretched 

 out. In the worst cases there is pronounced emaciation. 



1 On the other hand, potatoes grown in a dry sandy soil are stated to contain 

 more Solanine than those grown in other soils. 



