Strychnine
2 of the 7 encyclopedias on this shelf carry an entry for Strychnine. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
Important: Safety Warning This page contains a formula or preparation using substances now known to be dangerously toxic, such as arsenic, mercury, lead, or cyanide compounds. Exposure to these substances can cause severe poisoning, permanent injury, or death. In addition, this page recommends pest-control substances such as arsenic compounds, strychnine, or cyanide — in some cases applied to food crops. These substances are lethal to humans and animals, and their use is now banned or strictly controlled. This information has been left in for historical purposes but should not be acted upon. a vegetable poison from Java. It is a colorless, prismatic, crystalline substance extracted from the nuxvomica and the seeds of other plants of the same genus. These strychnine-producing plants are peculiar to the East Indies, particularly Java. Strychnine is without odor, but it is intensely bitter. One part of strychnine may be detected in 20,000 parts of water merely by the bitter taste imparted. Strychnine is an alkaloid--an energetic poison. A grain is a fatal dose for a man. Wheat, oats, or corn, steeped in water containing a little strychnine, may be dropped about their holes and runways to rid a farm of rats, gophers, or prairie dogs. If meal be stirred in after the grain has been soaked, the bitter taste is obscured, and the bait is more likely to be taken. Strychnine is the poison most often used for coyotes also. See Poison
Collier's New Encyclopedia (1921)
Important: Safety Warning This page contains a formula or preparation using substances now known to be dangerously toxic, such as arsenic, mercury, lead, or cyanide compounds. Exposure to these substances can cause severe poisoning, permanent injury, or death. This information has been left in for historical purposes but should not be acted upon. in chemistry, formula, C21H2N2O2, strychnia, a highly poisonous alkaloid, discovered in 1818 by Pelletier and Caventou in St. Ignatius' beans, and shortly afterward in Nux vomica seeds. It is obtained, together with brucine, by boiling Nux vomica seeds in dilute sulphuric acid till they become soft, crushing the seeds, and adding to the expressed liquid an excess of calcium hydrate, which throws down the two alkaloids. On washing with cold alcohol, brucine is dissolved, leaving strychnine in an impure state. When pure, it crystallizes in in colorless, tetragonal prisms, having a very bitter, and somewhat metallic taste, is almost insoluble in water, absolute alcohol, and ether, but soluble in spirit of wine and chloroform. The symptoms are very marked, and comprise violent tetanic convulsions, laborious respiration, from the tightening of the chest mu muscles, spasmodic contraction of the heart, and rigidity of the spinal column. These are succeeded by a short calm, after which they are again repeated till death or progress toward recovery ensues, the time being about two hours after taking the poison.