COUNTRY MANSIONS. 369 



merit, or to destroy the flies and other insects : and the large green frog might 

 be kept in ponds, and fed for culinary purposes, as it is in P'rance, Germany, 

 and Italy. The edible snail (Helix pomatia L.) might be kept, as it is near 

 Vienna, in large pits covered with boards, and fed with cabbage leaves and 

 other vegetables. The river crawfish (y^'stacus fluviiitilis) is not very common 

 in Britain, but it abounds in some parts of the Continent, particularly in the 

 marshy meadows of the Vistula, near Warsaw. These fish are reckoned a 

 great delicacy on the Continent, either boiled and eaten cold like shrimps, or 

 put into soup. In England they are found in meadows on the margins of 

 the Trent; and it might amuse a curious suburban resident desirous of 

 making experiments, to try to subject them to cultivation. The medicinal 

 leech, which lives chiefly on the spawn of fish or of frogs, might easily be 

 kept in small ponds, provided care were taken to prevent it from getting to 

 the fishponds ; during summer, the leeches come out on the grass in search of 

 snails and other food during night, and during winter they go into deep water. 

 The silkworm, wherever there is a white mulberry tree, or abundance of 

 lettuces, may be reared, and silk produced as an amusement. The eggs, 

 which may be procured in Covent Garden market in May and June, require 

 to be hatched in a temperature of from 60° to 80", on dry shelves, kept clean 

 and well ventilated, and the Avorms require to be carefully tended and well 

 fed. The silk, however, produced in England, is of no value but as a 

 curiosity, from its want of tenacity ; the thread only acquiring the necessary 

 toughness to enable it to be reeled and spun with a view to profit, in a hot 

 and dry climate. 



4.55. The Ice-house. — Ice may be kept in a dry cellar with as much ease as 

 coals, wine, or beer. All that is necessary, is to have the walls and roof of 

 extra thickness, so as to exclude heat; or to have them built double, or bat- 

 tened, and lathed and plastered. By the last process, a vacuity is formed 

 completely round the sides and roof of the ice-chamber ; and a similar vacuity 

 should be formed under the floor, communicating with a drain having a trap, 

 so as to convey away any water that may collect from the thawing of the ice, 

 without' admitting fresh air by the drain. This cellar should either have 

 double doors placed 2 or 3 feet distant from each other ; or, when the ice is 

 put in, an ample space should be left between it and the door, in order to 

 allow room for a large quantity of straw, to serve as a nonconducting medium 

 to the heat that would otherwise pass through the chinks of the door. In 

 filling an ice-cellar, the ice, having been first collected and laid down near it, 

 is broken into small pieces, and then pounded till it becomes a powder com- 

 posed of particles not larger than those of sand or coarse salt. It is then 

 carried into the cellar, and laid up in a heap, beating each layer as depo- 

 sited, so as to form the whole into a compact mass, and occasionally sprink- 

 ling a little water over it, in order to consolidate it. An improved method 

 consists in using water impregnated with salt, by dissolving 10 lbs. of common 

 salt in 10 gallons of cold water, and pouring it on the ice through a common 

 garden watering-pot, every 2 or 3 feet in thickness, as the cellar is filling. 

 The ice, in cellars filled in this manner, will be found when opened in sum- 

 mer, to consist of one solid mass of ice, which cannot be broken without the 

 pickaxe. It will keep much longer without thawing in the cellar, and also 

 much longer when exposed to the open air; because salt water, and conse- 

 quently salted ice, has a much less capacity for heat than fresh water or fresh 



2 B 



