August i, 1882.] 



THE TROPICAL AGRICULTURIST. 



179 



uudcr the proper conditions of temperature, moisture, 

 supply of oxygen, and presence of salifiable base is 

 continually converting ammonia and nitrogenous organic 

 matter, which has passed the putrefactive stage, into 

 nitrates. The nitrates are the chief form from which 

 most crops and especially the cereals assimilate their 

 nitrogen is now admitted generally, even by the few 

 physiologists who still cling to the belief that plants 

 can assimilate free atmospheric nitrogen ; the very 

 gi'eat use of this nitrifying organism is thus apparent. 

 It may be remarked in passing that this .Schizomycete 

 is able to efl'ect a change in a mineral substance, 

 ammonia, causmg its oxidation into nitric acid, all 

 other knowii organised ferments being concerned in 

 the transformation of organic bodies, and this is an 

 operation hitherto unsuspected in the life of any 

 Bacteria. 



Nitrification takes place in soils most rapidly in 

 the hot months of the year, and as a cereal crop 

 assimilates little or no nitrogen after June, but 

 merely transfers that ab-eady taken up and present 

 iii the roots, stems aud leaves to other organs, it 

 follows that, on a cornfield, in the late summer aud 

 the autumn mouths, nitrate will be formed and, will, 

 in the event of wet weather, be readily washed out 

 of the soil. 



Observations made during many years at Rotham- 

 sted, and recently published by Messrs. Lawes, Gilbert, 

 and \Varington,* show the extent to which this loss 

 of nitrates may occur. They find that on land un- 

 cropped aud unmauured, that is. a bare fallow, during 

 4 years 187S-1SS1, nearly forty-two pounds of nitrogen 

 per acre per annum, equal to nearly two and a half 

 hundredweight of ordinary nitrate of soda, was lost 

 by drainage. '1 hey also estimate that on land under 

 contmuous wheat cropiiing from ten to twelve pounds 

 of nitrogen per acre per amium was lost by drainage 

 from plots which received no nitrogenous manure. 

 When nitrogen is applied in the manure, consider- 

 ably larger quantities are lost in the drainage, aud 

 this is exclusive of that diffused into the lower layers 

 of soil below the reach of plant roots, and of that 

 which may under certain conditions be lost by de- 

 duction to elementary nitrogen. 



In an ordinary rotation the loss of nitrogen will 

 be considerably less than in these experiments, for 

 crops will often be growing for months after the 

 cereal crop is removed, and thus conserve the avail- 

 able nitrogen and store it up for future use. It is 

 however obvious, that, with a bare fallow favouring 

 the production of nitrates, followed by a wet season, 

 a very considerable loss of available nitrogen will occur 

 tlu-ough loss of nitrates, and it becomes a matter 

 for the farmer to consider whether it is to his ad- 

 vantage, for the sake of cleanmg his land, to take 

 the risk of this loss and supply the nitrogen at a 

 cost, in ammonia, salts, or Chili saltpetre, of nearly 

 a shilling per pound, or on the other hand, adopt 

 some system of cultivation and cropping by which 

 much of the loss may be obviated. On some soils 

 the growth of an autumn green crop would save 

 most of the nitrates and leave the land in fair con- 

 dition for a succeeding crop ; naturally the decision 

 as to the advisability of such a course must rest in 

 each case with the indiWdual farmer. 



The Agricultural mind appears to always requii'e a 

 panacea from the scientific man before it will accept 

 his results as of any use. At a recent meeting of 

 the Farmers' Club it was observed by a leading 

 agiiculturist, that, although Mr. Lawes (now Sir'.). B. 

 Lawes) had discovered the way in whicli nitrogen was 

 lost he had not told the farmer how to retam the 

 good effects of nitrogenous manures in adverse seasons. 

 The discovery of the manner in which the loss occurs 



* Journal of the Roi/al Ayriculiu al Society [2] xvii. and 

 xviii.; aud J ounal of Soeitti/ 0/ Arts, A^tU. "itb, 1882. 



is, however, an immense step in the right direction, 

 and moreover Lawes and his colleagues have clearly 

 shown that with a gi-owing crop on the laud the loss 

 is very greatly lessened. 



This bacterium of nitrification is but one of a great 

 number of the lower fonns of life now engaging the 

 attention of scientific men, whicli are, or ought to be, 

 of immense interest to the scientific pursuit of agi-i- 

 culture. The researches of Pasteur on the life histoi-y 

 of Bacillus of Aiitlu-ax, Aitken and Hamilton's In- 

 vestigations now being conducted into the causes pro- 

 ducing braxy and louping ill : and the study of the 

 organisms concerned in the changes which occur during 

 the souring of milk and the ripening of cheese are 

 kindred studies bearmg in a direct manner on the 

 daily practice of the fanner. Of no less interest too 

 is the biological work done by Kiihn and Liebscher, 

 which has traced the beet sickness to the presence of 

 a Nematode, while the investigations into the life 

 history of Hemileia vastatrix, the too well-kno\vn coffee 

 leaf disease, the Plasmidiophora, which is the proximate 

 cause of anbury in turnips, and the fungus of potatoe 

 disease, all point to the growing relation between the 

 kindred sciences of biology and agiicnlture. Illus- 

 trations might be multiplied almost indefinitely, but 

 these are of sufficient importance to show that the 

 work of the microscopist and biologist has a wide and 

 deep influence, first o{ all on tlie practice of agriculture, 

 and thi'ough it on the comforts and the pockets of 

 the consumers at large. — Nature. 



CULTIVATION OF CINCHONA IN THE UNITED 



STATES. 



Li response to the resolution presented in the House 

 of Representatives, relative to the growth of cinchona 

 trees in the United States, published in the Uil and 

 and Drug News on May 9, the following letter was 

 received from the Commissioner of Agriculture : — 

 Washington, May 12, 1882. 



In reply to the above resolution I have the honor to 

 state that for tlie past sixteen years the Department of 

 Agricultm'e has annually distributed cinchona plants, some 

 seasons to the amount of many hundreds, and that the 

 reports received afford but Uttle hope for success except 

 in Southern California, and, so far, no trustworthy ex- 

 periments have been made in tliat region. 



Some of the species will live in Southern Florida, notably 

 cincitoiM succirubra, which is one of the most; robust, as 

 also one of the most useful ; but the climate of that 

 State is not considered so promising for the establishment 

 of an experimental plantation as the higher lands of 

 Southern California. 



Dr. J. Elliott Howard, of England (high authority in 

 everything relating to the cinchona), in the transactions 

 of the Linnean Society, remarks that " it must be re- 

 membered that these are mountain plants, loving free air 

 and alternate mist aud sunshine, while the hot, close 

 atmosphere of tlie lower lands is alw.ays injurious to their 

 perfection as quinine-producing plants. 



The object sought to be obtained by the Department 

 in its distribution of cinchona plants was that of making 

 practical tests in the most promising localities in regard 

 to their permanent introduction ; this being the only safe 

 method of procuring such information. 



The climactic conditions under which the cinchona 

 flourishes in its native habitats have been repeatedly de- 

 scriljed and are now comparatively well known. The 

 management of an artificial cinchona plantation is now as 

 well understood as is the management of an orange group. 



In the India cinchona plantations the best results are 

 said to be obtained in a warm, equable, and very moist 

 atmcsphere, at elevations where the mean yearly temp- 

 erature indicates 64 ^ Fahrenheit, and in those established 

 in Saint Helena the plants flourish well at an elevation 

 of 1.500 feet above sea level, in rich lands, bathed in 

 moisture, the mean temperature for the year being 60 ® . 



It is shown in the reports of the Signal office that the 

 mean temperature for the year at San Diego is GO '^, the 



