On the Nature and Causes of the Decay in Potatoes. 547 
tire produce of a country. In all our methods, however, we must 
keep these three conditions in mind — dryness, coldness, and 
ABSENCE OF CONTACT. If jou could cjuite sccure the two first 
conditions, dryness and coldness, the latter, to a certain extent, 
might be dispensed with. In such cases small heaps of potatoes 
so disposed as to allow a current of air to pass through them 
would amply suffice. But in this varying climate, especinlly on 
the approach of warmer weather, or when the occurrence of con- 
tinued wet weather obliges us to close the ventilating shafts, the 
conditions for putrefaction are again resumed ; and, therefore, I 
do not consider such a mode of procedure a sufficient guarantee 
against failure. Where, therefore, potatoes have to be preserved 
out of doors, I would strongly recommend separation of the pota- 
toes, the one from the other, by some porous material. It matters 
little what that dry porous material is, but it is much to be pre- 
ferred if it is a disinfecter of putrid matter. In the metropolis 
there is a manufactory for the preparation of night-soil as a 
manure, in which a mixture of burnt clay and charcoal is mixed 
with the putrid soil. The effect is quite surprising, for the soil 
which possessed an insufferable odour previous to the mixture, is 
instantly deprived of smell. Burnt clay and charcoal have a 
remarkable disposition to absorb putrid emanations, and, there- 
fore, to prevent them communicating their state of decay to. or- 
ganic matter susceptible of their influence. Certainly, where 
burnt clay could be procured, it, of all other things, would be ad- 
visable for storing potatoes. But any dry matter will do, such as 
dry sand or ashes, and if it be porous an advantage will certainly 
be gained by constructing your heaps so as to admit of ventilation 
■ — that is, lay a dry foundation of stones, fagots, or any other thing 
that will admit the air, with an air-course in the middle. On this 
foundation put your layer of porous materials, then a layer of 
potatoes with a little of your porous materials shaken between 
them, and so continue your overground heap, leaving two or three 
air or vent holes. Of course, you will thatch this, and take the 
usual means of preventing frost. The practical details you should 
lecture to me about : it would be as useless as forward if I offered 
to you more than the principles upon which you should proceed. 
The Irish Commissioners proposed a packing stuff for the pota- 
toes, which has been found to succeed admirably, especially when 
the porous absorptive materials cannot be obtained. It consists 
in taking two or three parts of earth or clay as dry as can be 
obtained, and mixing them with one part of freshly burned lime. 
The lime takes the water from the clay, and, slaking itself at its 
expense, leaves the mixture thoroughly dry. This dry mixture 
is useful not only as a dry means of separating the potatoes, but 
also by destroying the vegetative powers of the sporulcs of the 
fungi. 
