and exercise and verj likely keep their normal weight 

 3»ear after year ; the latter possibly grow in weight 

 through getting fat and idle. Two such types exist 

 among plants. How often is one struck by the beauty 

 and perfect health, vigour and the regular advent of 

 the wild dowers by the wayside, often exposed to incon- 

 siderate violence and always to neglect, without any 

 attention save an unfavouralile oce from man and with- 

 out manure or extra nutriment, they year by year, cen- 

 tury by century, in the old spots, sturdily maintain 

 their peculiar '' habit " of growth and yield seed after 

 their kind. Oa the other hand the cultivated plant haa 

 certain demands put upon it. Its flowers or fruit must 

 be abnormally developed with all the accessories of per- 

 fume and luscious flavour, or food producing power. To 

 accomplish all ttiis) external aid and attention must be 

 called in and the power of such plants to obtain their 

 own nourishment must be supplemented by manures 

 artiflcially applied and here the sciences of Horticulture 

 and Agriculture step in. The artificial aid thus 

 rendered enables the growing plant to transfer some of 

 the energy, hitherto devoted to extracting and search- 

 ing for food together with the delay so involved, to 

 special development, modification, or increase, in fact 

 it becomes a question o/^«ai;i«^ q/"i'i»i6'. When in 1810 

 Liebig, by his lectures, drew attention to important 

 facts, hitherto too much ignored, thit while plants 

 during growlh accumulated aod re-arranged the ele- 

 ments entering into iheir composition ; they created 

 nothing and that while the surrounding atmosphere 

 might be relied upon to furnish the chief organic con- 

 stituents, the mineral material was all important and 

 its abstraction from the soil left Ihe latter so much the 

 poorer while the absence or insufficiency of the same 

 meant hopeless sterility. Astonishing as has 

 been ihe progress of chemistry since Liebig's 

 time his " Chemistry applied to Agriculture " 

 is still a classic work and must remain so 

 despite the fact that many of its conclusions are super- 



