342 Philosophy of Manures. 



plied will only hasten decomposition. What would have been 

 a stimulus to the living power, in preparing food, and exciting it 

 to act upon it, will, after death, only hasten its destruction. I 

 have since tried it frequently on fresh seeds, and found it gene- 

 rally to have the effect of accelerating their growth. In the 

 Mark Lane Express of April 5., a correspondent states that, 

 having steeped his mangold wurzel seed in water last year, he 

 dried some of it in lime powder, and found that this came up 

 three or four days before the other, and kept the lead, increasing 

 more in bulk all the year round. This is an accidental proof of 

 the theory being correct, produced without any preconceived 

 opinions. 



There has been so much said lately on the different Modes of 

 Heating, that the subject is well nigh exhausted. The subjoined 

 remarks I do not recollect to have seen made yet. Having seen 

 none of the houses fitted up in any of these new methods, 

 the remarks are merely theoretical. The uneasy sensation 

 felt in some stoves, I think, should arise more from the want of 

 moisture, than the want of motion, in the air. In very dry 

 sultry weather, out of doors, we experience something of the 

 same sensation ; but, no sooner does the moisture of approach- 

 ing rain begin to be suffused in the atmosphere, than the uneasy 

 sensation leaves us. The air, in a dry state, is a bad conductor 

 of electricity; and we are in something of the condition of a 

 person standing on a glass stool, and charged with electricity : 

 when the air becomes moist, the superabundance of electi'icity 

 is conducted away, moist air being a good conductor, and the 

 uneasy sensation goes off. Stagnant air, no doubt, will be pre- 

 judicial : but to a certain extent there is motion in the air in 

 all houses of the kind, from the tendency of heated air to 

 ascend, and of the colder to descend. I think it would have 

 been an improvement in Mr. Penn's method to have made the 

 cold air descend at the back of the house, and the heated air to 

 ascend at the front : a stratum of heated air would thus always 

 have been interposed between the cold atmosphere and the 

 plants, and danger of frost been much less. The mouths of 

 the drains for carrying on the circulation of the air should have 

 been level with the surface of the ground, or as nearly so as 

 possible ; because, whatever cold air passes the mouth of the 

 drain will not rise again, unless there are some pipes or flues 

 near the surface to heat it ; and the air in the drains should be 

 as much heated as possible to near the mouth, to keep up the 

 rarefaction of the air inside the drain, and consequent pressure 

 of that outside. Thei'e should be no water in the drains, as it 

 will lessen the rarefaction ; it would be better to have the water 

 in troughs above the pipes. Where bark pits are in the house, 

 pipes or drains should be run through the bed : the heat will 



