Recent Publications on Manures* 93 



constitutes the rudiments of the organs of plants. Liebig says, 

 nitrogen is found in every part of the vegetable structure; if it 

 is not found in the solids themselves, it is found in the fluids 

 that surround them. As to the data given as proof that ulmic 

 acid is always the result of decomposing substances, so many 

 different substances are thrown together in the manured heap, 

 and from the many different ways in which decomposition may 

 take place, according to the state of heat and moisture, and 

 their position with regard to each other, and the admission 

 or deprivation of atmospheric air, that it will not be easy to say 

 what may be the exact result. This is pointed out by Dr. 

 Madden himself, in the decomposition of sugar forming the 

 vinous fermentation by itself, and producing a very different 

 result when mixed with other substances. The hydrogen and 

 oxygen in sugar, starch, and lignin, though in the proportions 

 of water, are not in the state of water; and it does not follow in 

 the definition of the decomposition of sugar stated above, 

 that, though 8 atoms of oxygen are absorbed to form 4 of car- 

 bonic acid, the sugar must yield 8 of hydrogen at the same 

 time that it yields carbon. The 8 atoms of oxygen may have 

 been got from the atmosphere : it appears, indeed, from the 

 analysis, that either this or the 8 to form water must have 

 been got from the air, or there is some error in the printing, as 

 there is not oxygen sufficient for all in the sugar itself. If the 

 oxygen to form carbonic acid is got from the air, it cannot 

 affect the hydrogen of the sugar ; nor, though got from the 

 sugar, does it follow that hydrogen should be evolved, as the 

 hydrogen and oxygen in the sugar are not in the state of water. 

 It is probable, however, that decomposition often does produce 

 ulmic acid: the brown-coloured liquid from all manures is very 

 valuable, and probably contains both carbonate and ulmate of 

 ammonia, besides humus and apotheme ; and the further re- 

 searches of this enterprising chemist will undoubtedly elucidate 

 the subject still more. The water of peat moss contains ulmic 

 acid, Professor Thomson says : it is probably, however, as Dr. 

 Madden says, partly humus and apotheme, as well as ulmic 

 acid, that is in the water; and the solution of tannin it contains is 

 also brown-coloured. If this were poured on the ashes of burnt 

 wood, the smaller the branches and the younger the twigs the 

 better, ulmate of potash, a valuable manure, would be formed by 

 the action of the potash of the wood. This may be partly the 

 cause of the great effects of burnt ashes, applied to soils abound- 

 ing in refuse of vegetables, and in compost among woods. 

 Ulmate of potash is perhaps more the cause of growth than 

 is at present imagined. The ashes of burnt wood often pro- 

 duce immense effect on the stem and foliage of potatoes and 

 turnips, without a corresponding effect in the root : perhaps the 

 great absorbing powers of charcoal for the ammonia of the 



