EXPERT MENTAL. 



45 



No earlier analyses of the wheat globulin are on record. Weyl 1 was the 

 first to call attention to the presence of globulin in wheat, and says that 

 11 besides vegetable- vitellin I detected in the 10 per cent sodium-chloride 

 extract of the pulverized seeds of wheat, peas, oats, white mustard, and 

 sweet almonds a second globulin substance. ' ' This he calls vegetable- my osin 

 and gives its coagulation-point at 55 to 60. It is probable that Weyl in 

 some way mistook for a globulin the albumin already described. 



Later, Weyl & Bischoff ' 2 state : 



On investigating the proteins of wheat, one of us found chiefly an albuminous sub- 

 stance which, on account of its resemblance to myosin, was named vegetable-myosin. 

 This vegetable-myosin must be the mother-substance of the gluten, since in wheat meal, 

 together with it, other nitrogenous substances exist, at the most, only in very small 

 amount. 



On what experimental evidence this statement rests the writer has been 

 unable to discover, and in view of his experience he is at a loss to under- 

 stand it. 



Martin 3 considers wheat flour to contain a large amount of globulin of the 

 myosin type, coagulating between 55 and 60, precipitated by saturation 

 with sodium chloride and ammonium sulphate. Here again the small 

 quantity of albumin contained in the flour has evidently been mistaken 

 for a large quantity of vegetable-myosin. This perhaps is not surprising, 

 as the precipitates obtained by saturating sodium-chloride extracts with 

 ammonium sulphate appear very bulky, and in the absence of an actual 

 determination of the weight of these precipitates misleading conclusions 

 might easily be reached. The only globulin found by the writer in extracts 

 of wheat meal, either winter or spring wheat, is the one just described, 

 which in properties and composition closely resembles those globulins which 

 have been found in other seeds. 



THE PROTEOSE OF WHEAT FI,OUR. 



As already stated in describing the reaction of the extract freed from 

 globulin by dialysis, there was found in it one or more proteoses, besides 

 the albumin just described. These were almost wholly precipitated by 

 saturation with sodium chloride or by adding 20 per cent of this salt to the 

 solution, together with a little acetic acid. 



If the albumin is completely removed by heat and the filtered solution 

 then concentrated, a coagulum gradually develops. This substance must 

 be derived from the proteose-like protein, as this forms nearly if not quite 

 all the protein substance remaining in solution before concentration. If 



1 Weyl, Zeitschrift fur physiologische Chemie, 1877, i, p. 72. 



2 Weyl & Bischoff, Berichte der deutschen chemischen Gesellschaft, 1880, xm, p. 367. 



3 Martin, British Medical Journal, 1886, n, p. 104. 



