MALT LIQUORS. 



289 



the following method taken from Allen. 1 The maltose was estimated by 

 Fehling's solution, volumetrically, by the method in use in this laboratory 

 for the determination of cupric oxide reducing power. 2 The polariza- 

 tion is then observed in the original beer, the clarification being accom- 

 plished by means of lead acetate. The reading is taken on the circular 

 scale, and constitutes the total circular rotation. The number of grams 

 of maltose in IGOcc. of the beer having been ascertained from the results 

 obtained with Fehling's solution, it is multiplied by 2.78, which gives 

 the rotation due to maltose ; this result is deducted from the total rota- 

 tion, which gives the rotation due to dextrin. The angle found, divided 

 by 3.8G or multiplied by .259, gives the grams of dextrin in lOOcc of the 

 solution. These figures are based on the assumption that the polari- 

 scope used is one in which monochromatic light is employed, and that 

 the liquid is observed in a tube 200 millimeters in length. By dividing 

 the grams per lOOcc. by the density of the beer, the actual percentage 

 of maltose and dextrin will be ascertained. 



As considerable interest is attached to the nature of the polarizing 

 bodies in malt liquors, I append the polarization given by the samples 

 examined. It is a very easy and satisfactory determination to make, 

 the beers being readily clarified by acetate of lead, giving bright, clear 

 solutions. The figures given are in divisions of the cane-sugar scale, 

 and for the normal beer, the dilution of one-tenth incident upon the ad- 

 dition of the lead being corrected by reading in a 220-millimeter tube; 

 the instrument employed was a Laurent polariscope, in which mono- 

 chromatic light is employed. 



The polarization was in all cases right-handed. 



ALBUMINOID MATTEKS. 



The albuminoids were determined by weighing 10 grams of the beer 

 into a schiilcheu, evaporating to dryuess, and burning with soda lime 

 in the usual way. The nitrogen found x G.25 is given as the per cent- 



1 Page 275. 



2 Fully described iu Bulletin No. 15, page 32. 



