326 True and Hunkel, The Poisonous Effect Exerted etc. 



Here, electrolytic dissociation can hardly be regarded as 

 playing an important role in giving to fresli pyrogallol Solutions 

 their poisonous properties. The physiological results are seen to 

 Vary considerably as presented in Tables XI, XII and XIII. 

 The length of time elapsing between the making of the Solution 

 and the time of using it is seen to exert a marked effect. The 

 Solution used immediately after preparation gives a toxic value 

 of 1/1600. The Solution used in XII was fresh but was not 

 diluted far euough to reach the limit. After standig five days, 

 this same stock Solution was again used, the toxic action having 

 in the meantime increased, giving 1/6400 gram-molecule per liter 

 as the first dilution in Avhich the lupines survived. Table XII 

 shows in addition an interesting phenomenon, indicating the pro- 

 gressive development of the poisonous activity of the Solution on 

 Standing. In the dilution containing 1/800 gram-molecule of 

 pyrogallol per liter, the radicles made during the first 17 hours 

 spent in the Solution a growth nearly normal for distilled water 

 and ordinary temperature, viz. 9,5 mm and 8,0 mm respectively. 

 In no other instance did the radicles succumb within the time 

 limits here observed after making so great a growth. This can 

 be unterstood when the chemical behavior of pyrogallol under 

 circumstances similar to those here found is taken into account. 

 Ph. de Clermont and P. Chautard^) find that pyrogallol is 

 slowly oxydized in the air to purpurogallin, having the composition 

 C20H16O9, from which they prepared a sodium Compound of the 

 formula C20 II12 Na4 O9 and a barium Compound, C20 IIi2 Ba2 O9. 

 Purpurogallin, therefore, seems to be an acid, but how many 

 carboxyl and how many hydroxyl hydrogens the Compound 

 contains cannot well be even surmised from our present chimical 

 knowledge of the substance. The great toxic eftect of the 

 decomposed Solution would seem to indicate, hewever, that it 

 contains at least one carboxyl group, which upon dissociation 



+ 

 furnishes the strongly toxic H iun er ions. 



The toxic value of a completely dissociated mono-basic acid, 

 as HCl, is, according to Kahlenberg and True**), 1/6400 for 

 lupines. For other acids undergoing complete dissociation, the 

 same value is found for every acid hydrogen atom, carboxyl 

 hydrogen in the case of organic Compounds, one-half this concen- 

 tration for acids containing two acid hydrogen atoms untergoing 

 complete dissociation, and for other acids in like ratio. 



') P. de Clermont and P. Chautard. (Berichte der deutschen. 

 chemiechen Gesellschaft. Bd. XV. p. 1457.) 



^) Kahlenberg and True. Bot. G a z. XXIl. 1896. p. 92, 



