24 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



(6) The toxicity in other cases is due to a very sensitive glucoside 

 which has the property of dissolving the red blood corpuscles. It is 

 found in Amanita phalloides ard is so powerful that even in a dilution 

 of 1 in 125,000 it is still operative upon the red blood cells of ox blood. 

 Abel and Ford have given it the name of Amanitahemolysin and have 

 found that it is destroyed by heating to 70 C. and by the action of 

 digestive ferments. Ford has been able to prepare an anti-poison or 

 an anti-hemolysin, the action of which is to completely neutralize 

 the blood-laking properties of this glucoside. 



(c) A third class of principles have been isolated and these belong 

 to the group of bacterial toxins. Their real nature is unknown, but 

 they have been thus classified by Ford by virtue of their causing 

 characteristic lesions in animals after a definite latent period. The 

 best known of these is Amanita-toxin, which is probably the most 

 toxic principle known and occurs in Amanita phalloides. It is the 

 cause of death when this fungus is eaten. 



(d) In other fungi the active principle is in the nature of an acid. 

 The one most carefully studied is the agaricinic acid occurring in 

 Polyporus officinalis. In Helvella amara, fungus used in medicine 

 in Cochin China, the active principle is helvellic acid. Kobert 

 states that he has found mushrooms that emitted an odor of hydro- 

 cyanic acid and that poisonous symptoms resembling those produced 

 by this acid sometimes occur in mushroom poisoning. 



In testing fungi Ford employs the dried fungus and makes an 

 aqueous extract, using 6 gins, to 50 c.c. of water. These solutions 

 are then diluted to a strength from 1 in 20 to 1 in 200 and sub- 

 cutaneously injected into guinea pigs, when, if they are made from 

 poisonous fungi they show within twenty-four hours the character- 

 istic symptoms and reactions of either acute or chronic intoxication. 



Literature. Ford, Science, July 23, 1909, p. 98; Kobert, Lehr- 

 buch der Intoxikationen ; Blakeslee and Gortner, Biochemical 



Bulletin, 1913, 2, p. 542. 

 * 

 SACCHAROMYCES, OR YEASTS 



Yeasts are unicellular organisms and are usually regarded as being 

 greatly reduced sac-fungi. They belong to the family Saccharomy- 

 cetes and of which there are several classes, the principal one of which 

 is Saccharomyces, being the organism used in the manufacture of 

 beer and compressed yeast. The real Saccharomycetes are capable 

 of forming endospores and are further subdivided according to whether 

 they ferment maltose, as brewer's yeast, or not. 



The yeast cell is more or less globular or ovoid in form and varies 



