PRESERVATION OF FRUITS BY SECLUSION. 193 



grain, nor can the rest be so securely kept for several years 

 as it would be in pits. The custom however has long pre- 

 vailed, and is still to be found throughout Europe, and 

 even in Asia and Africa. 



The grains which are consumed in Algiers and Tunis, 

 or which are exported thence, are, after having been well 

 dried in the sun, deposited in trenches cut in the rocks, 

 and having their sides lined with straw. The Count of 

 Lasteyrie has found the same mode followed in Malta, 

 Sicily, Spain, and Italy. There are even some countries 

 where the governments have caused trenches to be con- 

 structed, in which the cultivators of lands might deposit 

 their harvest till a favorable season for selling them. 



In order to secure a perfect preservation of the grain in 

 trenches, it is necessary to make use of certain precau- 

 tions, without which the entire loss of it must be hazard- 

 ed : the means of security are as follows. 



1st. The grain should never be put into trenches till 

 it is perfectly dry ; it must therefore be first exposed to the 

 sun for several days, and during that time be often turned, 

 that every part of it may become equally dry. 



2d. In constructing the trenches, choice must be made 

 of a dry soil, or a rock free from chinks, that there may 

 be no danger either from dampness or the filtration of 

 water. The walls of the trenches may be made with such 

 cement as the Romans used in the construction of their 

 aqueducts ; this is composed merely of lime and pebbles ; 

 the walls of these aqueducts were raised in frames, and 

 the surface of them carefully polished ; I have visited the 

 remains of some of them in various parts of France, and 

 have found them everywhere present the same appear- 

 ance : I am convinced that this cement is impenetrable by 

 water, and of a solidity more than sufficient for construct- 

 ing the sides of trenches.* 



3d. The third precaution consists in excluding the air 

 completely ; if this fluid should gain admittance, it must 

 necessarily convey in at the same time moisture and oxy- 

 gen, the two principles of germination ; the presence of 

 air will likewise favor the existence and multiplication of 

 insects ; whilst if the trench be full of grain, and well 

 closed, all the air which it contains will be changed into 



* The mode of building may be used which the Count of Lastejrrie 

 has proposed in his work, entitled Des Fosses pour la Conservation des 

 Grains. 



17 



