ADULTERATION OF WHEAT-FLOUR. 



427 



be inferred, that the natural nutriment of the plant being deficient, the 

 haulm dies, the cells of the tuber soon turn black and decompose, and 

 fungi are developed as in most other decaying vegetable substances. 



fig. 205. 



Potato Starch-granules, sold under the name of British Arrow-root, and used to 

 adulterate flour and bread. Magnified 240 diameters. 



This will undoubtedly explain the most prominent symptom of the 

 potato-disease, the tendency to decomposition ; and is a point in which 

 the microscope confirms the result of chemical experiment : for it has 

 been found that the diseased potatoes contain a larger proportion of 

 water than those that are healthy. A want of organising power is evi- 

 dently the cause of this deficiency of starch ; but we fear the microscope 

 will never tell us in what the want of this organising force consists."* 



The adulteration of articles of food and drink has long been a 

 matter of uneasy interest, and of strong, though vague misgiving. 

 Accum's Death in the Pot, between thirty and forty years ago, awoke 

 attention to the subject ; which has since been more or less accurately 

 explored by Mitchell, Normandy, Chevalier, Jules Garnier, and Harel ; 

 and has now at length derived a singularly lucid exposition from the 

 researches so far as they have extended, and their extent has been 



* Professor Quekett's Histology of Vegetables. We would also refer the reader to 

 an admirable work on Fungi, by Arimini, an Italian botanist, 1759, 



