ISo. 199.] 445 



ed in the cereals and in milk. The first exists in the largest degree 

 in animal flesh, and the latter in gum, sugar, starch, spirits, wine, beer, 

 and lastly, the various kinds of fat. But perhaps the most singular 

 facts connected with the question — " What does man live upon ?" 

 are bearing upon tea and coffee, which are now amongst the necessa- 

 ries of civilized life, as the Paraguay tea is to the South American. 

 In all these substances chemistry has discovered precisely the same 

 substance. And finally chemistry has brought to light the fact, that 

 all those substances used by man as food are compounds of the four 

 simple substances — oxygen, carbon, hydrogen and nitrogen. In the 

 second lecture on this subject, Schleiden alludes to the opinion thus 

 broached by Liebig, that the vegetable world lives upon the carbon, 

 ammonia, am' water of the atmosphere ; and very properly asks — if 

 this be th: case, of what use is manure 1 Liebig's idea was, that it 

 was to supply the mineral part of the plant alone, and that the farmer 

 would get as much benefit if he' burnt manure heaps, and strewed the 

 land with the ashes. With this view he sought to revolutionize our 

 whole agricultural system, by the recommendation of a mineral manure 

 he has discovered, for the preparation of which he has taken out a 

 patent in England, and sold it to Messrs. Muspratt & Co. His aim 

 is to furnish to every soil and plant a proper compost of those mineral 

 substances which the plant requires and the soil is deficient in, and in 

 such a peculiar state of combination, that the substances shall be so- 

 luble enough to be taken up by the plants, and yet not so readily 

 soluble that the rain can wash away any considerable quantity. 



Every farmer who has tried Liebig's manure is aware of its failure ; 

 and we think that this this has been principally caused by his want of 

 attention to the difference of climate between Germany and England. 

 In the clear sunshine of the former it may be possible to dispense 

 with ammonia in the manure, but certainly not in England or Scotland. 



We regret extremely that Liebig should have so publicly pledged 

 himself to certain views, as we have no doubt but that his failure has 

 damaged the cause of scientific agriculture, and thrown it back by se- 

 veral years. 



