438 THE PARKS AND GARDENS OF PARIS. [Chap. XXV. 



seedlings of garden-crops likely to be destroyed by birds or insects 

 are frequently raised under the cloche. 



In a recent number of the ' Comptes Kendus,' M. Th. Schlosing 

 points out that the power of absorbing mineral ingredients in 

 solution from the soil is diminished by cultivating plants under 

 glass, and thus lessening the amount of evaporation from their 

 surface. A Tobacco-plant so grown absorbed 17 per cent, of 

 mineral matter, instead of 20 per cent., as it would do under 

 ordinary circumstances. The production of vegetable acids was 

 diminished by one-half— that of resin and cellulose to a less 

 extent; while the nitrogenous ingredients were not materially 

 decreased. Starch was present to the extent of 20 per cent., 

 instead of to 100th per cent. only. Thus when evaporation is 

 reduced in amount, a portion of the starch remains unused, and 

 consequently accumulates in the plant. Assuming the correctness 

 of M. Schlosing's conclusions, the immense 

 importance to cultivators is obvious ; as 

 the two staple food-ingredients, the nitro- 

 genous matters and the starchy ones, 

 can be augmented by limiting evapora- 

 tion. 



Usually the cloche is made without a 

 knob, as that appendage renders their 

 '^lS?:;/;.Z//^;:„.f' P^^^age ^ ^^^h greater difficulty and 

 increases the cost, so that practical men 

 use only the one without the knob. When not in use the 

 cultivator puts his cloches in some by-place, in little piles of 

 half a dozen each, small pieces of wood being placed on the 

 top of each to prevent them from settling down firmly on each 

 other. Workmen used to them carry two or three in each hand 

 in conveying them from place to place, by putting a finger 

 between each. In commencing to use them in our gardens 

 it would be well to see that they are placed in some spot where 

 they will not be in danger of breakage. The cloche must not be 

 confounded with the dark and very large bell-glass that was in 

 common use many years ago in our market-gardens, and which 

 may yet be seen here and there. These were even dearer than 

 the hand-glasses which superseded them. The French cloche 

 does not cost one-fourth so much as a hand-li<?ht — and, moreover. 



