Cfeap. .] Flour, M&czlage, &, 155 



rnuft be confe fifed that this defer iption will not apply 

 in all refpects to the more imperfect fpecies of farina. 



If a handful of wheat- flour is taken and kneaded in 

 a veflel of water, underneath a ftream from a cock, 

 the water carries off a fine white powder, and the 

 kneading rrwft be continued till the water pafies off 

 clear. The flour is then found to be feparated into three 

 fubftancesj a greyifti and elaftic matter remaining 

 in the hand, which is called the glutbous or vegeto- 

 animal part ; a white powder depofited by the water, 

 which is the fecula or ftarch ; and a fubftance held in 

 folution by the water, which is of a faccharine mucila- 

 ginous nature. 



The glutinous matter exifted before in the flour in a 

 pulverized form, and acquires its tenacity by imbibing 

 a portion of the fluid, but is totally iftfoluble in it. It 

 has fcarcely any tafte, is elaftic, ductile, and of a 

 whitifh grey colour. When drawn out, it extends to 

 the length of about twenty times its diameter before it 

 breaks, and appears as if compofed of fibres placed 

 befide each other, according to the direction in which 

 it has been drawn. If the force ceafes, it recovers its 

 original form by ks elafticity. When dry it is femi- 

 tranlparent, "and refembies glue in its colour and ap- 

 pearance. If it is drawn out thin when firft obtained, 

 it may be dried by expofure to the air, and in that ftate 

 has a polilhed furface, refembling that of animal 

 membranes. If it is expofed to warmth and moif- 

 ture while wet, it putrefies like an animal fubftance. 

 If this gluten in its dried ftate is placed on burning 

 coals, or held in the flame of a candle, it exhibits the 

 characters of <*n animal fubftance ; it crackles, fwells 

 and burns, exactly like a feather or piece of horn. By 

 diftillation it affords, like animal fubftances, alkaline 

 water, concrete volatile alkali, and an empyreumatic 

 E 4 oil. 



