112 PROTEIN POISONS 



undoubtedly present, but the crystalline masses were 

 largely leucin, and no tyrosin was obtained in purified 

 form. From the crude crystals, after many and repeated 

 crystallizations, what was thought to be leucin was obtained 

 pure, melting at 264 to 265 uncorrected, or 269.42 to 

 270.46 corrected. The crystals were thin plates charac- 

 teristically grouped, and sublimed readily. From another 

 5 per cent, sulphuric acid extract of albumin poison was 

 obtained a large mass of crystals in characteristic tyrosin- 

 like sheaves, and giving a deep Millon reaction. These 

 were undoubtedly tyrosin, though at the time no melting- 

 point was taken. 



Properties of the Haptophor or Non-poisonous Group. Leach 1 

 has investigated this split product with the following 

 general results: After cleavage of the protein with alkaline 

 alcohol, the haptophor remains undissolved. It is collected 

 on a filter, then transferred to Soxhlets, and for some days 

 extracted with 95 per cent, alcohol. This is for the purpose 

 of removing as thoroughly as possible the alkali which it 

 has absorbed from the alkaline alcohol. This cannot, 

 however, be wholly washed out by this method, and it is 

 possible that in part it is held chemically. After this 

 extraction the substance is easily reduced to a fine brownish 

 powder. On burning it puffs up, gives off the characteristic 

 odor of nitrogenous compounds, and leaves a copious ash 

 containing phosphate. The solubility of the haptophors 

 from different proteins differs widely; that from egg-white 

 is wholly soluble in water, while that from the cellular 

 substance of the tubercle bacillus is only sparingly soluble. 

 However, it is only the part soluble in water from any of 

 these haptophors that is of special interest. The studies of 

 Leach, referred to, were made with the non-poisonous 

 portion of the colon bacillus. This is mainly soluble in 

 water, giving an opalescent solution from which a light- 

 colored sediment is deposited on standing, leaving a clear, 

 golden brown solution. The sediment is not soluble in 



1 Jour. Biolog. Chem., 1907, iii, 443, 



