CHAPTER V 



SCROPHULARINE^. 



Foxglove {Digitalis purpurea L.). The Foxglove has been recog- 

 nized as poisonous for centuries, and one of its trivial names is Dead 

 Men's Bells — a name suggestive of the consequences of taking it. It is 

 the source of the well-known drug ; and cases of human poisoning have 

 been very common, though by no means always fatal — indeed, Esser 

 says "seldom resulting in death." Animals are not known to touch 

 this plant, but it may possibly be included in rough meadow hay, though 

 only one case, in which two cows and a horse became ill after eating hay 

 containing dry foxgloves, has come to notice {Veterinary Record, 1906). 

 Cornevin, however, experimented on animals, and found the following 

 amounts of fresh leaves capable of causing death in the animals specified : — 



Horse . . 120-140 grammes (4 to 5 oz.) 



Ox . . 160-180 „ (5-5 to 6-5 oz.) 



Sheep . . 25- 30 „ (0-88 to 1 oz.) 



Pig . . 15-20 „ (0-5 to 0-7 oz.) 



The weight of dried leaves would be only one-fourth of these figures. 



All parts of the foxglove are poisonous, but especially the seeds, and 

 the leaves are more active before than after the flowering period. Culti- 

 vated varieties are stated to be less toxic than the wild species. The 

 effects of poisoning may terminate fatally in a few hours, or if small 

 quantities are taken regularly the poison may be cumulative and induce 

 chronic poisoning. 



Toxic Principle. The foxglove contains several poisonous gluco- 

 sides, investigated by Kiliani, Schmiedeberg, Cloette, Bourquelot, 

 Herzig, and others. The following substances are toxic: Digitalin 

 (C35H5gOi4 or C36H58O14) in the seeds and leaves ; Digitonin (C54H92O28 

 or C55H94O28) in the seeds ; Digitalein, only in small quantity ; Digitoxin 

 (C34H54O11) in the leaves; and Digitin. The toxic property of the 

 foxglove is not lost on drying or boiling. 



