. A manual of poisonous plants, chiefly of eastern North America, with brief notes on economic and medicinal plants, and numerous illustrations. Poisonous plants. 164 MANUAL OF POISONOUS PIvANTS when taken into the body of man or animal. In fact, such decomposition pro- ducts are known and as most of them, probably all, are basic, containing nitro- gen, they have been grouped with that general class of vegetable alkaloidal sub- stances called Ptomains. If other poisonous substances than Ptomains are developed, they are not known at the present time. In addition to these poison- ous substances
. A manual of poisonous plants, chiefly of eastern North America, with brief notes on economic and medicinal plants, and numerous illustrations. Poisonous plants. 164 MANUAL OF POISONOUS PIvANTS when taken into the body of man or animal. In fact, such decomposition pro- ducts are known and as most of them, probably all, are basic, containing nitro- gen, they have been grouped with that general class of vegetable alkaloidal sub- stances called Ptomains. If other poisonous substances than Ptomains are developed, they are not known at the present time. In addition to these poison- ous substances that arise as decomposition, other poisonous substances are pro- duced by certain bacteria which are strictly synthetic, that is not produced by the breaking down of complex compounds into more complex forms. The exact chemical nature of these substances is not understood, the reasons for this being that they are extremely unstable, it being impossible to heat them without destroying, and they cannot be recognized by any known chemical means. They must be distinguished and differentiated, and often detected only by animal inoculation and experimentation. These soluble substances excreted by the bacteria are called toxins. The term toxin is rather an unfortunate choice, because it refers simply to their poisonous properties. In the broad sense, any poisonous substance is a toxin, but in the sense in which it will be here used, toxin indicates specific bacterial poisons excreted into the medium in which the ^ *® I* Fig. 23. Bacillus cloaceae from corn, cause of corn disease, also found in sewage. Supposed at one time to pro- duce toxic substances to which was attributed the corn stalk disease. After I ?'^' l^- , ^°?''"'"T?" (.Bacillus Sorghi). b Young plant infected with the organism. o leaf and sheath, c Bacilli. Modified after Kellerman and Swingle. organism is growing, and producing upon inoculation, anti-toxins. In addition to the products above
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