THE POTATO. 645 



afterwards pitting them till spring, it would most probably answer better 

 not to expose them to the process till more immediately before planting, 

 in order that the excitement to growth might go on without an intermediate^ 

 check. (N. in G. M. 1842.) 



1416. Taking up and preserving a crop. The art of keeping potatoes, 

 whether for culinary purposes or propagation by sets, is founded on the 

 following principles: "Potatoes may be viewed as tuberous stems, edible 

 only when in a blanched state ; for exposure to light is injurious to their 

 nutritive qualities, more especially if vegetation is excited. The latter may 

 be checked, it is true, by various means ; but nothing can prevent the tubers 

 from becoming green if long exposed to direct light. That this affects them 

 even in winter, in some degree, there is no doubt ; but as the heat of the 

 season advances, the influence of light becomes much more evident ; and 

 when some time exposed to light, instead of being wholesome, they ultimately 

 become, to a certain extent, poisonous. Potatoes ought, therefore, to be 

 kept as much as possible in the dark. They ought not to be exposed to 

 light a single day after they are dug up ; they are even deteriorated in qua- 

 lity by spreading out to dry previously to storing up. The less they are 

 dried the better, for drying injures the skin. If the skin, and perhaps a 

 portion of the substance immediately below it, is made to part with its 

 natural juices by drying, it is not at the same time rendered incapable of 

 absorbing moisture if presented to it ; but the natural juices, although 

 watery, are yet not water ; and, therefore, the latter substance being foreign, 

 must, when introduced into the tuber, prove injurious to it. Fermentation 

 is sometimes brought on by putting moist potatoes together in large masses 

 in a warm situation, and of course changes the whole substance, and anni- 

 hilates the vegetative principle. It should, therefore, be carefully guarded 

 against, by not throwing the potatoes into too large heaps, but rather laying 

 them up in long ridges, with divisions of earth at intervals corresponding 

 with the quantity of potatoes that are intended to be taken out at once. If 

 potatoes are dried unavoidably, they should not be again wetted till such 

 time as they are about to be cooked. No good judge of the nature of 

 potatoes would choose to purchase out of the washed heaps exposed in towns 

 in preference to such as are unwashed. It is not well to use straw next 

 potatoes, for it becomes decomposed by the moisture, and, by its decomposi- 

 tion, carburetted hydrogen is formed. The colour of the flesh of the white 

 kidney potatoe has been known to be changed from white to yellow when 

 boiled, in consequence of a straw covering having been placed next them in 

 the ridge, and at the same time a bad flavour communicated. If the above 

 observations are attended to, failures to any extent worth noticing in the 

 vegetation of the sets will not occur. Potatoes have been known to have 

 been taken up in a very wet state indeed, and buried in small quantities in 

 moderately dry soil ; but no failure in the sets resulted from such practice." 

 (jV. in G. M., 1842.) Potatoes intended for seed, as we have seen 

 (1407), should be taken up before they are ripe ; but those for keeping 

 should be mature. The greatest care is necessary, in both cases, not 

 to make the slightest wound on the rind of the tuber, which, if done, 

 is certain of sooner or later bringing on decay. They may be preserved in 

 cellars which are out of the reach of frosts, in pits hi dry sandy soil, or in 

 ridges above the surface, five feet wide, and of any convenient length, 

 first covered with turf, if it can be had, placing the grassy side uppermost, 



