PROTEIDS AS POISONS. 55 
foods. 1 Its action has been studied by Chittenden 2 and his pupils. It is a 
ferment of intense activity, and acts well in neutral, acid, and alkaline 
solutions, especially at 60° C. The ferment itself is associated or identical 
with a proteose-like substance in the juice. The products of its action 
(proteoses and peptone) are like those of other proteolytic ferments. 
I have alluded to these two ferments because tiny have formed the basis 
of very thorough investigations, not because they are in any way exceptional 
occurrences in the vegetable kingdom; as already stated, such ferments 
probably play an important part in all plants, by converting tin- insoluble 
proteid of the seed into the soluble nitrogenous substances of the sap. 3 
Pboteids as Poisons. 
The line between food and poison is easily crossed. When, a few 
years ago, the idea was first mooted that proteids may ad as poisons, it 
was received with incredulity in many quarters : but there can now be 
no doubt that it is a fact. 4 
The best known of the vegetable proteid poisons are : — 
1. Those contained in the seeds of jequirity (Abrus precatorius). 
Warden and Waddell 5 named the poisonous substance abrin. S. Martin lj 
separated the two proteids — a globulin and a proteose — of which it is 
composed. The material is used as a drug to produce conjunctivitis. 
2. The proteid associated with or identical with papain (S. Martin). 
•'!. Ricin, tin- poisonous proteid in castor-oil beans. 7 
4. Lupino-toxin from Lupinus luteus? 
The most important of the animal proteid poisons are — 
1. Snake poison. 
2. Proteids in the serum of certain fishes (conger eel. muraena, etc.). 9 
3. Proteid poisons found in certain spiders, 10 and in the stinging 
apparatus of many insects. 
-4. Ordinary peptones and proteoses; 03 gr. of commercial peptone 
per kilog. of body weight is in dogs usually fatal, when injected into 
the blood. 
5. Nucleo - proteids. — These were called tissue fibrinogens by 
Wboldridge, and cause intravascular clotting when injected into the 
blood (see "Coagulation of Blood"). 
ij. Poisonous proteids produced by bacterial action. This subject 
has recently received much attention, and opens up the whole subject 
of toxins and antitoxins. To go into this matter thoroughly would 
1 Bull. Fharm., Detroit, 1891, vol. v. p. 77. 
2 Trans. Conned. Acad. ArtsandSc, New Haven, 1891, vol. viii. ; Jutn-n. Physiol. , Cam- 
bridge and Loudon, vol. xv. p. 249. 
3 See further Green's papers already quoted ; also J. I!. Green, " On the presence of 
vegetable trypsin in the fruit of Cucumis utilis ami other plants,'' Ann. agronomiques, 
Paris, tome xix. p. 508 ; Neumeister, Ztschr. f. Biol., Miinchen, Bd. xxx. Another recent 
paper on the subject (J. Hjort, C'entralbl. f. Physiol., Leipzig, 1896, lid. x. S. 192) shows 
that there are similar ferments in fungi. 
4 Nencki's opinion that poisonous proteids are more labile than other proteids can 
hardly lie considered an explanation of this fact (" Ueber die labile Eiweissstoffe, " Wchnsehr. 
f. Pharm., 1891, No. 29). 
5 '■ Xon-Bacillar Xature of Abrus Poison," Calcutta, 1884. 
6 Brit. J/ed. Journ., London, 1889, vol. ii. p. 184. 
7 Stillmark, Pharm. Centr.-BL, Leipzig, 1S90, Bd. xxx. S. 650. 
H Schmidt's Jahrb., Leipzig, 1888, Bd. cciv. S. 10. 
9 Mosso, Jahresb. ii. '1. Fortschr. •! . Thier-Chem., Wiesbaden, Bd. xviii. S. 92. 
'"Robert, Sitzungsb. d. Dorpater naturforseh. Gesellsch., 1888; Centralbl. ''. d. //<"/. 
Wissmsch., Berlin, 18S8, S. 511. 
