Ui 



THE FARMER'S MAGAZINE. 



about the fourth part of its volume of carbonic acid 

 gas. 



The plants were grown in the open air, sheltered from 

 the rain and dew. 



The soil of the vase No. 1 had no nitrate of soda. 

 The soil of the vase No. 2 had 0.310 grains. 

 The soil of the vase No. 3 had 0.620 „ 

 The soil of the vase No. 4 had 2.480 ,, 



During vegetation the plants remained very strong, 

 the leaves were of a fine green. Here are their respec- 

 tive dimensions at the end of the experiment. 



Length of Widlh of Weight of 

 Height, the largest the largest the dried- 

 leaf, leaf. up plants. 



No. 1 I Mitral"! I - '"'=''^' li inches 4.70 | 7.055 grs. 



o 



2 /♦;' 0.310 er.'\ 4i inches 2 inches 0.30 g 13.000 grs. 



3 .| ° 0.62') gr. > 4| inches 2| inches I inch 19.022 grs. 



4 V5 2.480 gr.y 9 inches S| inches I J inch 52.545 grs. 



By taking off the weight of the seeds from the weight 

 of the dried plants, we find that the organic matter 

 elaborated during vegetation was as follows : — 



Organic matter formed by No. 1, not 

 having received any soluble ni- 

 trogen 6.045 grains. 



By No. 2 having received 0.05115 



grain of soluble nitrogen 11.2685 ,, 



By No. 3 having received 0.10230 



grain of soluble nitrogen 17.515 ,, 



By No. 4 having received 0.4312 



grain of soluble nitrogen 50.84 ,, 



The influence of the soluble nitrogen was manifest, 

 and it was not without astonishment that in the experi- 

 ment No. 2 we found that 0.05115 grain only of ni- 

 trogen introduced into the soil was sufficient to increase 

 two-folds the organic matter of the Helianthuscs ; also 

 the proportion of the weight of the seed to that which 

 was : : 1 : 4.6 of the dried crop, in the cultivation of 

 which no nitrate bad been used, became — 



: : 1 : 7.6 in cultivation No. 2, as above. 

 : : 1 : 11.3 in cultivation No. 3, ,, 

 : : 1 : 30.8 in cultivation No. 4, ,, 



The analysis showed in the helianthuses No. 1 grown 

 in the soil without any nitrate of soda. 



Nitrogen 0.08215 grain. 



In the seeds there was, nitrogen 0.05115 ,, 



Nitrogen generated in fifty days' vega- 



tation 0.03100 ,, 



For the plants grown in a soil to which nitre had been 

 applied, the quantities of nitrogen found led to the 

 following results : — 



Nitroffen t.t.. 

 Nitrate contained in f'^'^^^ll 

 added. the nitrate and "^"t^"^ 

 the seed. P'=*"^^- 



IlelianthusNo. 2, 0.310gr, .. 0.10230 gr. .. 0.09610gr. 

 Helianthus No. 3, 0.620 „ .. 0.15500 „ .. 0.15035 „ 

 Helianthus No. 4, 2.430 „ .. 0.46035 „ .. 0.:3y905 „ 



Traces of nitric acid were found in the soil of experi- 

 ment No. 2 and No. 3. In the soil of experiment No. 

 4 there was a little less than 0.465 grain of nitrate of 

 soda ; and in none of the plants submitted to the action 

 of that salt, did the nitrogen assimilated by the organism 

 exceed that which the nitrate had introduced. 



What is must striking in this s.cond snits of experi- 



ment is to show not only as much a nitrogenous sub- 

 stance introduced into the soil contributes to tiie growth 

 of the plant, but to demonstrate besides hov.' much the 

 organic matter elaborated by the plant increases 

 through the intervention of the smallest quantity of 

 soluble nitrogen. 



One may also convince liimself by examining the 

 figures expressing the quantity of carbon fixed by the 

 helianthus, that the decomposition of the carbonic acid 

 gas was so much the more conspicuous, as the plant had 

 at its disposal a greater quantity of nitrate of soda, or, 

 in other terms, more nitrous manure. 



contained m Nitrogen n^ner formed 



Experiments, in the seeds introduced by • '^^5 ^°^^^,°- 



-I. xi -i. i. in titty days 



weighmg the nitrate. , „ . i:„,, 

 1.705 graiSs. vegetation. 



No. 1, .. 0.05115 gr. 0.00006 gr. 6.1535 gr. 



No. 2, .. 0.05115 gr. 0.05115 gr. 11.1600 gr. 



No. 3, .. 0.05115 gr. 0.10230 gr. 17.5150 gr. 



No. 4, .. 0.05115 gr. 0.40920 gr. 50.8400 gr. 



^ , J • J • Average of carbonic 



■r, . . Carbon contained in . , s , 



Jijxperiments. ., .. acid decomposed 



'^ the organic matter. • oa \ 



° in 24 hours. 



No. 1 2.4645 grains . . 2^ cubic inches 



No. 2 4.4640 ,. ..4^ ,, 



No. 3 7.0060 „ .. 6| „ 



No. 4 20.3360 „ ..17 



From the whole of these researches it follows — 



1st. That phosphate of lime, the earthy and alca- 

 line salts indispensable to the constitution of plants, 

 exercise, however, no action upon vegetation, except 

 when they are combined with matters capable of yielding 

 soluble nitrogen : 



2nd. That those soluble nitrous matters which the 

 atmosphere contains, intervene in too small a propor- 

 tion to determine, in the absence of a nitrous manure, 

 an abundant and rapid vegetable production ; 



3rd, That saltpetre combined with phosphate of lime 

 and silicate of potash, acts as a complete manure, since 

 helianthuses grown under the influence of that mi.\ture, 

 for vigour and size bear a comparison with those which 

 had been grown upon a garden strip strongly manured. 



I will add, in conclusion, that it is very remarkable 

 to see a plant going through all the phases of vegetable 

 life, germinate and ripen — in one word, attain its normal 

 development, when its roots are growing in a calcined 

 sand containing, instead of organic debris in a state of 

 decomposition, salts of a great purity, combined sub- 

 stances perfectly defined, such as nitrate of potash, basic 

 phosphate of lime, alkaline silicates ; and to ascertain 

 that by means of those auxiliaries, all taken from the 

 mineral kingdom, this plant progressively increases the 

 weight of its organism by fixing the carbon of carbonic 

 acid, the elements of water, and by elaborating with the 

 radical of nitric acid, albumen, cassine, &c., that is 

 to say, the nitrogenous principles of milk, blood, and 

 muscular flesh. On the other hand, there is probably 

 more analogy than may be supposed between the salts I 

 have just mentioned and manure. Dung, in which 

 Braconnot did not find less than fourteen substances, 

 singularly changes its constitution when it has sojourned 

 in a soil suitably pulverized. Fermentation persisting 

 in the soft parts, the slow combustion which humus, 

 black earths, those advanced terms of the decompositon 

 of organized bodies and the dejectionsof animals undergo. 

 The action which air, water, soil, exercise upon all thes6 

 matters, are, after all, so many causes why dung gives to 

 plants alkaline and earthy salts, phosphates, and, as re- 

 ci^ii-'nts of soluble nitrogen, nitr^'tes and ammonia. 



