156 



THE FARMER'S MAGAZINE. 



Nitrogen 

 Gra ins 



In both plants 0-24862 



I had placed into the eoil nitrate 17'05, equal to 235972 



Nitrogen from the nitrate not assimilated 211110 



In seventy-two days, these Helianthuses absorbed from 

 the atmosphere only G.572 grains of carbon. Here, 

 again, I am induced to attribute tliis languid state, 

 which was manifested in the vegetable life of the plant 

 even from its earlier growth, to the fact that it did not 

 find in the soil any phosphate of lime, for it must have 

 been developed with the help of the small portion of 

 that substance always contained in the seed. In fact, 

 there is no seed in which are not found, at the same time, 

 although in limited proportions, the essential agents of 

 manure — phosphates and soluble nitrogen. 



We can, besides, form an exact idea of the utility of 

 phosphates for the development of organism when it is 

 allied to a nitrogenous manure, by comparing the veget- 

 able matter formed by the plants which have grown with 

 the co-operation of a complete manure, as in the experi- 

 ments of 185G, with those that were developed under 

 the action of a nitrogenous manure from which phos- 

 phates were excluded :— 



gs 



2 W 



O H 

 >S O 



to 1^ 

 o ^ 



Erg 



1 have verified this result, which demonstrates the 

 insufficiency of soluble nitrogen when it operates with- 

 out the help of phosphate, by adding co the soil a 

 manure other than saltpetre. I selected carbonate of 

 ammonia, because it is always found in stable manures. 

 Third Experiment. — Vegetation of the Helian- 

 thuses, in the open Air, in a Soil destitute of Phos- 

 phate of Lime, and being manured vith Carbonate 

 of Ammonia. 

 The soil xcighing 12400 grains was formed of a mix- 



ture of white sand and fragments of bricks. These sub^ 

 stances, like the flower-pot,* had been calcined. After 

 having damped the soil with pure distilled water, the 

 seeds of the Helianthus were sown in it : they weighed, 

 together, 1 798 grains. When germination was ac- 

 complished, I began to introduce, every time the soil 

 was watared, a certain quantity of carbonate of ammo- 

 nia, by pouring a solution of a determined quantity. 



On the seventeenth day the first leaves were formed. 

 Like the cotyledons, they were of a very deep green 

 colour. 



On the twenty-seventh day tbe plants were 2^ inches 

 high ; the cotyledons were discoloured. The second 

 leaves were developed ; and indication of the third leaves 

 was just discernible, but, already, several black spots 

 were visible upon the first leaves. 



On the seventy -fourth day the highest stem was 6 

 inches high ; the first and second leaves were withered, 

 the third leaves were spotted, the fourth and the fifth of 

 a beautiful green colour. A floral bud, small but very 

 well formed, was visible. 



The two plants weighed, when dried up, 17'515 grains. 



During the cultivation I had introduced into the soil 

 1029-lG cubic eighths of an inch of solution of car- 

 bonate, containing 29 -1240 grains of soluble nitrogen. 



The analysis indicated in the two plants 0-6466 gr. of 

 nitrogen. 



The dried-up plants weighed between ten and eleven 

 times as much as the seed. 



There had been 15-71 7 gr. of vegetable matter formed, 

 in which there were 6-923gr. of carbon assimilated in 

 seventy-four days, which indicates that upon an average, 

 in every twenty-four hours, the plants had decomposed 

 34-76 cubic eighths of an inch of carbonic-acid gas. This 

 is exactly what had happened with the Helianthuses 

 grown under the sole influence of saltpetre, and this 

 coincidence is very remarkable. There is, however, 

 between the two results a difTerence which is not less 

 extraordinary ; and that is, that the Helianthuses grown 

 under the influence of saltpetre have fixed 0-268 gr. of 

 nitrogen, whilst those that grew under the influence of 

 carbonate of ammonia fixed 0.651 gr., nearly three 

 times as much — a very singular constitution, since the 

 result is that one hundred parts of the dried-up plant con- 

 tain 3-67 gr. of nitrogen, that is more than is contained 

 in one hundred parts of the seed. This is the first 

 time that in the course of my researches I have observed 

 such a fact. Constantly does the whole of a plant 

 furnish, under analysis, a less quantity of nitrogen than 

 the seed ; and the difference has always been so much the 

 more remarkable, as the plant was more developed, 

 from the reason that it had elaborated more cellular 

 tissue, pectlc produce, oily matter — in one word, more 

 principles in the constitution of which there is no 

 nitrogen. I cannot explain this anomaly, for this is 

 one undoubtedly to admit, that which is after all pretty 

 probable, that carbonate of ammonia is apt to act two 

 perfectly distinct parts in the chemical phenomena of 

 vegetation. 



In the one, it would act in supplying the plant with 

 soluble nitrogen, it would then concur like the nitrates 

 in the formation of the albuminous matter of the 

 tissues ; in the other it would intervene in the same 

 manner as mineral manures, acting as an alkaline 

 carbonate — as, for instance, carbonate of potash — its base 

 uniting with vegetable acids to constitute ammoniacal 

 salts. In the conditions in which the Helianthuses 

 were grown, there could not be any other salts there. 

 Ammonia was the only alkaline substance which they 

 could absorb. Thus, in this hypothesis, which I will 



♦ The flower-pot made iu Pans, notwithstanding its being 

 calcined, still retained some uitifttes, equal to 00031 grain of 

 uitiate of potash. 



