158 PnYTOTOXIXS axd zootoxixs 



a nerve-tissue poison, and it also seems to act as a hemolysin and ag- 

 glutinin (Bellesme and Sanarelli), but Todd'"' found it without ac- 

 tion on corpuscles and not capable of combining with nervous tissues. 

 Calmette '■•" gives the lethal dose for a guinea-pig as 0.5 milligram, 

 while Phisalix and Varigiiy put it at 0.1 milligram and state that 

 scorpion blood is also poisonous. Wilson " found the toxicity of the 

 venom equal to 0.1 gram per million, that is, one gram of poison will 

 kill 10,000,000 grams of guinea-pig, hence it is much stronger than 

 cobra venom. It is quite stable, and keeps many months in an ice 

 chest; is not affected by heating to 100° for a brief period, but is de- 

 stroyed after 12 or 13 minutes' heating. The active constituents are 

 precipitated by saturating with ammonium sulphate, or by an excess 

 of alcohol. The average amount of toxin in an Egyptian scorpion 

 {Buthus quinque striatus) is sufficient to kill about 35 kilos, which 

 agrees with the fact that fatal poisoning by this scorpion is rare in 

 adults, but reaches 60 per cent, in children. The venom is harm- 

 less when taken into the stomach, and is said to be made inactive by 

 ammonia, calcium hypochlorite, and peroxide of hydrogen. Calmette 

 claims that antivenin for cobra in part neutralizes scorpion poison, a 

 statement which could not be corroborated by Todd, who succeeded, 

 however, in preparing an efficient antiserum by immunizing horses 

 with scorpion venom. A large number of naturalists and raconteurs 

 have furnished interesting tales of suicide by scorpions, which are 

 more than improbable in the light of our present knowledge concerning 

 natural immunity. Many animals seem to possess more or less im- 

 munity to scorpions (AVilson), especially such wild animals as are 

 much exposed to them. 



SPIDER POISON 



The poison apparatus of the spiders consists of two long pouches 

 lying in the thorax and extending into the jaws, at the apex of which 

 the poison is discharged. Some of the larger members of the family 

 are very poisonous, e. g., the Malmignatte {Lathrodectes tredecim- 

 guttatas), of the vicinity of the lower Volga in southern Russia, is 

 said to have destroyed 70,000 cattle in one year, the bite being fatal 

 in 12 per cent, of all cases, although rarely killing man. Other 

 members of this species in Chili, ^Madagascar, and other countries 

 are not much less venomous. Kobert has studied the poison of Malmi- 

 gnatte and found it distributed throughout the body of the spider, 

 even in the eggs, and resembling in nature the snake venoms. It is 

 destroyed by heating, and seems to be of protein nature; the chief 

 effect is u])()n llie nervous system and heart. '^ 



f.r. Jour, of Tlvtriono, 1000 (9), fif). 

 r.n Ann. Inst. "Pastour, ISO.'i (9), 2.32. 



5 T Records of Kfr\i)tiini (iov'1.. School of Med.. 1!)04: iibsl. in Jonr. of riiysiol., 

 1904 i'M), p. xlvii'i 



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