150 MANUAL OF POISONOUS PLANTS 



in cultures of Spirillum and putrid animal matter; mydalein, guanidin. The 

 cholin group includes neuridin, betain, and muscarin. The muscarin has been 

 referred to elsewhere. The neurin is intensely poisonous, and atropin is an 

 antidote to neurin. Tetanin produces tetanus. Tetanotoxin from tetanus pro- 

 duces tremor paralysis and violent convulsions. Mydatoxin contained in putrid 

 horse flesh is poisonous in large doses, causing lachrymation, diarrhoea, and 

 convulsions. Tyrotoxicon, isolated by Vaughan from milk, is toxic. The suso- 

 toxin isolated from hog cholera is said to be quite toxic. 



ORGANIC ACIDS. 



The last group of ooisonous substances includes the organic acids, the most 

 important of which is oxalic acid. This is widely distributed both in the free 

 state and in combination with lime soda and potash in the vegetable kingdom. 

 It occurs in some species of the geranium, spinach, Phytolacca dccandra, pie 

 plant, Rwnex Acetosa and in Atropa Belladonna, in connection with potash. In 

 Russian Thistle and Salicornia it occurs in combination with sodium. In clover, 

 apple twigs, begonia, and many other plants it occurs in the form of so-called 

 compound aggregate crystals, or rosettes of calcium oxalate, in the onion and some 

 other plants of simple crystals. In aroids and Virginia Creeper it appears in 

 the form of needle shaped crystals, known as raphides, which are formed during 

 the metabolism of the plant, the oxalic acid being set free and uniting with the 

 lime in the plant to form calcium oxalate. 



Oxalic acid is commonly used by dyers and calico-printers and also by cur- 

 riers and harness makers for cleaning leather, to remove iron stains, to bleach 

 straw, etc. 



Several cases of poisoning have been attributed to the use of plants (like 

 the sheep sorrel, oxalis, etc.), that contain large amounts of oxalates. 



Quite a number of cases of poisoning from this acid are reported, especially 

 in Europe. The smallest dose of oxalic acid known to have destroyed life, ac- 

 cording to Dr. Taylor, is 60 grains. Oxalic acid acts upon the central nervous 

 system. There is temporary loss of voice, burning in the throat, burning in the 

 stomach, vomiting, especially bloody matter, pulse weak, locally it acts on the 

 mucous tissues. 



