248 ON THE SEED. 



so long as the plants have sufficient room to grow. Of 

 course, they must not be cramped and stinted for space ; 

 for large plants require extensive accommodation : but 

 the reason why a confined space is advantageous to small 

 plants has not hitherto been ascertained. The heat gen- 

 erated by the fermentation of manure, is also more favor- 

 able to germination than the heat of a stove. 



Caroline. That, I think, is easily accounted for. The 

 heat of a stove is of a drying nature, whilst that of the fer- 

 mentation of manure is always accompanied by moisture, 

 which will accelerate the swelling of the seed and burst- 

 ing of its coats. And why should not this be the reason, 

 that a hotbed is preferable to a hothouse, for the purpose 

 of raising plants from the seed ? For the one is heated 

 by fermentation, the other by a stove. 



Mrs. B. The pots in which they are sown are fre- 

 quently placed in beds of manure in a hothouse. Besides, 

 the same argument holds good with regard to greenhouses: 

 the smaller the house, the better it is calculated for the 

 culture of small plants. It has been suggested, that small 

 plants being always placed in the front and lowest rows 

 of the greenhouse, and hot air having a tendency to rise, 

 they occupy the coldest strata of air. 



In the preparation of hotbeds, the manure of horses is 

 preferable to that of cows, as it more readily decomposes, 

 and enters into combination with vegetables. That of 

 pigeons possesses this quality in such a remarkable degree, 

 that it is dangerous to germination, by precipitating it too 

 much. 



Caroline. The seeds, however, are, I believe, never 

 sown in manure itself, but in pots of earth which are sunk 

 in it ; the plant, therefore, benefits only by the heat and 

 the evaporable particles. 



Mrs. B. That is true. Little or no manure should be 

 mixed with the earth contained in the pots, in which ger- 

 mination takes place ; for the seed, at that period, far from 

 being in want of food, requires to get rid of a surplus of 

 carbon. 



1354. What comparison is made between the heat of a stove and that 

 generated by fermentation 1 ? 1355. What reason does Caroline give 

 for this comparison'? 1356. What has been suggested as to the plac- 

 ing of small plants in greenhouses'? 1357. What comparison is made 

 between different kinds of animal manure'? 1358. What is said of 

 mixing manure with the earth in which the germination of seeds is to 

 take place'? 



