52S 



THE TROPICAL AGRICULTURIST 



[Feb. 1, 1887, 



"FRUGES CONSUMERE NATL" 

 [A Vegetarian Restaurant has been opened in the 



Strand opposite the Royal Courts of Justice.] 

 I have always loved a vegetable dinner, I delight 

 In the Cr6cy soup or Oontie on the menu of the night ; 

 The Potato needs no praises, there is rapture too I ween 

 On the face of every c/oicnnet at the mention of the Bean ; 

 And, likewise Sir Henry Thompson, I can feel my heait 



aglow 

 At the thought of all the merits of the pleasant Haricot. 



I am very fond of Cabbage, and the tender Spinach 

 begs, 



Though it isn't quite en regie, to be served up with 

 poached eggs ; 



Then the Cauliflower is charming, and the Celery when 

 viewed 



Fresh and crisp from out the garden, or artistically 

 stewed. 



While surely on one esculent we're all unanimous, 



Is there aught that's more entrancing than thy taste- 

 Asparagus ! 



All must love the lively Lettuce ; we have reason too 



to bless 

 Cruciferte for sending us the piquant Watercress ; 

 Upon any list of salads let the true Tomato stand. 

 With the Endive and the Beetroot as supporters of 



each hand ; 

 There the Cucumber awaits us, and we fain would 



keep aliee 

 Both the Tarragon and Chervil and insinuating Chive. 



There is poetry in Mushrooms, and the Leutil too 



can please, 

 And a thrill goes through my midriff at the thought 



of early Peas ; 

 I am grateful to the Turnip and the Parsnip looking 



pale : 

 There's the Salsify seductive and the delicate Seakale ; 

 But the bard shrinks back from one task, for no 



mortal ever can 

 Do full justice to the comfort that the Onion is to 



man ; 



Then we'll hasten to the Griffin, for a little way be- 

 yond 



Are the Vegetarian dining-rooms of Messrs. Spiers and 

 Pond; 



And the Doctors too are with us, men of note in 

 London town, 



Risdon Bennet, Milner Fothergill, and also Crichton- 

 Browne ; 



They have told us very plainly that of health we should 

 be winners, 



If we ate less meat, indulging in more vegetable 

 dinners. 



—"Punch," Noxtmher 20. 



SOURCES OF NITROGEN AS PLANT FOOD. 



A correspondent (" P. T. I.") in asking the follow- 

 ing questions opens up a wide and an important en- 

 quiry : — 



1. Nitrate of ammonia being the chief compound 

 from which the roots of plants absorb nitrogen, is the 

 greater amount of it formed in the air (and carried to 

 the earth by rain) or in the earth Y 



2. In reference to the nitrate of ammonia formed in 

 the soil, how is its nitric acid formed, and how is its 

 ammonia formed? Is its ammonia chiefly produced 

 by the decay of organic substances, or absorbed from 

 the air, or brought down by rain? 



3. Do the roots of plants absorb ammonia uncom- 

 bined with any other substances, but merely dissolved 

 in water ? 



4. Do the roots of plants absorb sulphates, carbon- 

 ates and phosphates of animouia in a state of Nature ? 



5.' Is ammonia, uncombiued with auy other sub- 

 stances, brought down to the earth by rain ? 



6. In reference to the ammonia present in the soil, 

 is the chief amount of it (a) brought down to the 

 earth by rain, (i) absorbed from the air by the soil, 



or (c) produced by the decay of organic substances in 

 the soil H 



Plants obtain the elements of which they are built 

 up partly from the atmosphere and partly from the 

 soil. The water and most of the organic matter, 

 making on an average from 90 to 95 per cent of the 

 total weight of the plant, comes from the atmosphere, 

 either directly through the leaves or indirectly from 

 the soil by rain, and then to the plant through its roots. 

 Nitrogen exists in soil.s in three combinations— with 

 carbon, with hydrogen, and with oxygen. When ia 

 combination with carbon it is very insoluble in water, 

 and it is in this form that we find by far the greater 

 part of the nitrogen that exists in soils. The nitrogenous 

 organic matter of the soil has been derived either 

 entirely from the decay of vegetable dibris left in the 

 land by preceding generations of plants, or pos.sibly 

 to some extent from past applications of farmyard or 

 of other organic manures. It is also a fact that 

 besides the residues of crops soils receive certain amounts 

 of nitrogen from the atmosphere in the form of ammonia 

 and nitric acid, but the quantity of these substances 

 contributed annually by rain varies in different years 

 and places. The average of many experiments on the 

 Continent gives 10 23 lb. of nitrogen per acre. The 

 average of some English experiments is but 7'2f) lb. 

 Rain also furnishes small quantities of alkaliu'i chlorides, 

 especially in the neighbourhood of the sea, and about 

 18 lb. per acre per annum of sulphuric acid. Although 

 the amount of ammonia directly absorbed by the soil 

 from the atmosphere may in some soils be much larger 

 than is shown by the analysis of the rain, yet the 

 total nitrogen acquired, though most important as 

 tending to counterbalance the losses of plant-food 

 which the soil annually suffers, will have little effect 

 on the present fertility in comparison with the large 

 accumulation of nitrogenous matter resulting from 

 previous crop residues, and decay of animal refuse. 

 In all kinds of soils there exist very minute under- 

 ground organisms, called " bacteria," invisible to the 

 eye, the function of which is to separate the carbon 

 and hydrogen from the nitrogen, and to unite it with 

 oxygen. But to effect this lime must be present in 

 the soil, and the compound so formed is called nitrate 

 of lime. Nitrogen in combination with hydrogen forms 

 ammonia, and the substance with which most gardeners 

 are acquainted as ammonia-salts is obtained from an 

 extinct vegetation. Nitrogen in combinaticm with oxj'gcn 

 forms nitric acid, these combine under the influence 

 of the electric discharges in the atmosphere, nitrous 

 acid being formed; this is converted into nitiic acid 

 by the action of ozone, or peroxide of hydrogen, and 

 is brought down bj' rain. Ammonia cannot exist as 

 such for any length of time in the soil, neither is it 

 taken up by plants in that form. The facility with 

 which ammonia and other nitrogenous substances are 

 converted into nitric acid by the oxygen of the soil 

 is so great, that nitrates become by far the most im- 

 portant source of plant food. The uncombiued nitro- 

 gen of the atmospliere is not appropriated by 

 plants. Plant roots take up all the dilTusible sub- 

 stances which are present in the water which they 

 draw from the soil; but the feeding power of roots 

 is by no means confined to the taking up of ready 

 formed solutions, for they are also capable of attacking 

 some of the solid ingredients of the soil which they 

 render soluble and thela ajjpropriate, for the building 

 up of their vegetable fabric. The best of all manurial 

 applications are those which supply both phosphates 

 and ammonia or nitrogen. — Gardeners' Chronicle. 



Gow'g Te.\ Witherixcv Machine has been erected 

 on Mariawatte and, as telegraphed yesterday, 

 pirvate trial was made of it yesterday, to be followed 

 by a public exhibition of its capacities tomorrow. 

 According, to one account, it is claimed for this 

 machine that, by its means, perfectly cured tea 

 can be packed within four hours of the green 

 flush having been taken from the trees. If so, the 

 machine will turn all existing ideas of fermenting 

 and manufacture upside dewa. 



