Dr Davy on an Economical Mode of using the Potato. 189 



to prepare a portion of the potato in this way : it would afford 

 a variety in the form of diet to the poor ; the starch would serve 

 to make puddings, and answer all the purposes of arrow-root, 

 for which it is so often sold in the shops ; and the cellular 

 parts dressed as a cake with a little sugar, or as a biscuit, 

 might serve the purpose occasionally of bread. It might be 

 useful also at sea on long voyages ; and, if mixed with a cer- 

 tain portion of potato-starch, it might be considered as al- 

 most identical with the potato itself, possessing, as the mix- 

 ture would, all the ingredients of the potato not soluble in 

 cold water ; and, as regards the starch, its quantity might be 

 so regulated as to be in the best proportion. 



I may offer another economical suggestion, which may, I 

 think, be deserving of attention, with a view to avoid waste 

 as much as possible. Potatoes, on being boiled, whether in 

 their skins or without them, yield to the water a portion of 

 starch, and also of a nitrogenous matter, making a weak 

 broth. This broth has a pleasant taste like that of a very 

 dilute animal broth ; and tested by corrosive sublimate and 

 tincture of iodine, affords indications of the presence of al- 

 buminous matter as well as of starch. Moreover, the extract 

 obtained, by evaporating it to dryness, burns, emitting a 

 smell of animal matter burning, and yields an ash containing 

 a notable portion of potash and phosphate of lime. I may 

 remark that these substances, with magnesia and peroxide 

 of iron, are also found in the potato-skin, in which also they 

 are probably combined with an azotised matter, which may 

 render even the skin likewise nutritive. 



In conclusion, may I be permitted to observe, that when 

 famine is threatening a people, ought not attention to be 

 given to every substance of native produce available, capable 

 of affording nourishment, such (to mention a small number) as 

 the acorn, the horse-chestnut, the ground-nut \ These contain 

 a large proportion of starch, and the two first mentioned a 

 good deal of albuminous matter. They are not pleasant, it 

 is true, to eat, on account of the presence of a bitter prin- 

 ciple, which, probably, may be destroyed by roasting or some 

 other simple process. In the instance of the sheep, the horse- 



