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



this conjecture, considering how low is the estimated nutri- 

 tive power of starch, and from the circumstance that the cel- 

 lular fibrous part, when dried, yields ammonia on destructive 

 distillation, and, when incinerated, a comparatively large pro- 

 portion of the phosphates of lime and magnesia, with some 

 potash and a little silica. 



Reflecting thus, I was induced to have the cellular fibrous 

 portion, after the extraction of the greater part of the starch, 

 dressed for trial. It was put into the hands of the cook, 

 with directions to make it into biscuits, baking them in the 

 oven. So dressed, very slightly browned, they were agree- 

 able to eat at the time, and they kept remarkably well. Be- 

 fore I left England I examined one which had been wrapped 

 in paper and deposited in a close cupboard, and it was then 

 good after twelve months' keeping. To give it further and 

 severer trial as to its power of keeping, I brought it with me 

 to the West Indies, and placed it here, in Barbadoes, in a 

 close press, with some other vegetable substances, which 

 had been preserved a long while in England by being merely 

 dried by exposure to the air, cut into thin slices, such as tur- 

 nip, carrot, and apple. On examining these very recently, 

 after having been nearly a year and a half within the tropics, 

 I found them all, with the exception of the biscuit from the 

 potato, spoilt, being covered with mildew, whilst it was 

 hardly perceptibly affected by mildew, and, after exposure 

 for half-an-hour to sunshine, had not the slightest smell of 

 mildew ; and moreover, when tasted by a very competent 

 judge, accustomed to the luxuries of the table, was pronounced 

 to be not unpleasant. 



Does not the foregoing admit of practical application ? 

 "Whenever there is reason to suppose that potatoes are in- 

 fected with the prevailing disease, would it not be judicious, 

 without loss of time, to subject them to the process men- 

 tioned, — ^first, extracting their fecula, which has often been 

 recommended and practised ; and ^next, collecting and pre- 

 serving as an article of food, by drying and baking, the cellu- 

 lar fibrous portion ] Even in favourable years, when there is 

 no risk of the potato rotting, it might often be advantageous 



