1020 



SCIENCE. 



[N. S. Vol. XV. No. 391. 



seeds when I'ipe are commonly used as fod- 

 der, but the growing plant is quite poison- 

 ous to horses, sheep and goats. It was 

 noted that when the dry leaves were 

 crushed and moistened with water they 

 gave off an odor of hydrocyanic acid. An 

 investigation revealed the presence of a 

 glucoside, lotusin, which was hitherto un- 

 known. Under the influence of an enzyme, 

 also present in the plant, the lotusin was 

 transformed into prussic acid, sugar and a 

 new coloring matter called lotoflavine. It 

 will thus be seen that this glucoside is very 

 similar in its properties to amygdalin and 

 also to linamarin from common flax. 

 These glucosides may cause poisoning when 

 taken into the stomach but are innocuous 

 when administered hypodermically, for in 

 the latter case they are excreted unchanged, 

 while in the former they are apt to be de- 

 composed by the acids and enzymes of the 

 stomach. 



The class of amaroids has not been well 

 investigated chemically, but we know sev- 

 eral compounds belonging to the group 

 which are extremely toxic. Cicutoxin is 

 the poisonous constituent of the common 

 water hemlock, Cicuta maculata, a plant 

 which probably causes more fatal cases of 

 poisoning in the United States than any 

 other plant. Digitoxin, one of the poison- 

 ous constituents of the foxglove. Digitalis 

 purpurea, is poisonous to cats in a dose of 

 0.4 of a milligram per kilogram of body 

 weight, while andromedotoxin, the poison- 

 ous constituent of many Ericaceous plants 

 such as the common laurel, Kalmia lati- 

 folia, and the rhododendrons, is still. more 

 toxic, being fatal to frogs and to birds in 

 a dose of 0.1 of a milligram per kilogram 

 when injected subeutaneously. But, as we 

 shall see, it is miich less fatal when fed to 

 birds. It is much more fatal to frogs than 

 is atropine or strychnine. 



The alkaloids are so well known that they 

 do not need much discussion here. Aconi- 



tine is one of the most poisonous, being 

 fatal to birds in the small dose of 0.07 of 

 a milligram per kilogram when injected 

 hypodermically. 



The enzymes are not very well known, 

 and in most cases they are not toxic. Some 

 of them are, however, capable of causing 

 disorders when injected under the skin. 

 Very closely related to these are the toxal- 

 bumins which embrace the most deadly of 

 all of the poisons, as may be recognized 

 from the fact that they are the poisonous 

 constituents of the venom of snakes and 

 spiders, of many pathogenic bacteria, and 

 of the most poisonous fimgi, such as Aman- 

 ita phalloides. We shall have more to say 

 about these substances later. 



Nearly all of the active principles which 

 have been isolated from plants have also 

 been studied toxicologically, and have been 

 classified in different ways, but chiefly with 

 regard to the character of their effect and 

 the organ most seriously poisoned. We 

 thus have those which cause marked ana- 

 tomical changes of tissues, those that prin- 

 cipally affect the blood and those that do 

 not cause any marked anatomical lesions. 

 The fatal dose, also, has in many cases 

 been established, so that we can often tell 

 how much of a given substance will kill a 

 given animal in a given time. In this de- 

 termination it is absolutely necessary, of 

 course, that the animal tested be a healthy 

 one, otherwise a fatal lesion may be pro- 

 duced by the poison simply on account of 

 the previous weakening of the affected 

 tissue by the disease. The time and dose 

 limitations of poisoning are not essential 

 in our accepted definition of a poison, for it 

 considers only derangements of function. 

 If these are produced even by commonly 

 edible substances, such as sodium chloride 

 or sugar, we are obliged to say that under 

 the special conditions of the case in hand 

 these substances are poisonous. Sugar is 

 thus poisonous to a diabetic patient, while 



