409 



grammes, stem, leaves and roots included. 

 Analysis of the plant and the soil gave the fol- 

 lowing results : — 



Grames. 



Nitrogen in the plants, 0.1126 

 do in the soil, 0.0452 



0.1578 



Nitrogen in 1.110 gr. of nitre, 0.1536 

 do in 0.062 gr. of seed, 0.0019 



0.1555 



Grain of nitrogen in plant and soil, 



after four months vegetation, 0.0023 



From the facts connected with this experi- 

 ment, M. B. draws the following conclusions : — 

 3U The nitrogen of the nitrate absorbed is as- 

 similated by the plant. 2. For every equiva- 

 lent of nitrogen assimilated, the sunflower re- 

 ceives into its composition one equivalent of 

 potash. 3. We find in the soil nearly the whole 

 of the nitrate which the plant does not absorb. 

 4. The action of the nitrate of potash, which 

 is most decided from the very commencement 

 of vegetation, manifests itself with the neces- 

 sary addition of any putrefying organic matter. 



In order to judge better of the effects of 

 nitre, M. B. performed another experiment, 

 which consisted in placing on the 10th of May, 

 1855, two seeds of the sunflower exactly in the 

 conditions in which the seeds of the previous 

 experiment had been placed. The only differ- 

 ence was in withholding the nitrate of potash 

 from the substances added to the calcined sand. 

 The plants in this case grew very slowly, were 

 throughout of a pale green color, and in June, 

 wdien the other plants w r ere 0.20 metres in 

 height, these were only 0.06 and 0.08 m. The 

 nitrogen obtained by the growth of these two 

 plants in the open air for four months was only 

 0.0033 gr. 



Similar experiments were also made with the 

 nitrate of soda, which is the nitrate most in use 

 at present for agricultural purposes. The re- 

 suls were also similar. From both sets of ex- 

 periments it seems highly probable, that the 

 alkaline nitrates act on vegetation with as much 

 readiness, and perhaps w r ith more energy, than 

 the salts of ammonia. The plants which lan- 

 guished in soil without any addition of a ni- 

 trate, flourished vigorously in the same soil 

 when a nitrate was added — as vigorously indeed 

 as they did, in one experiment, in a highly ma- 

 nured garden soil. The decomposition of car- 

 bonic acid by the leaves of plants, or the ab- 

 sorption of carbon into their composition, 

 seems by these experiments, to be in some way 

 dependent on, or subordinate to the previous 

 absorption of some manure of a nitrogenous 

 kind. 



One result of some importance arising from 

 M. B.'s demonstration that the nitrates act fa- 

 vorably on vegetation, by means of their ab- 

 sorption, directly or without the concurrence 

 of substances in a state of decay, is that w r e 

 are thus furnished with an explanation of the 



influence, in part, of water used in irrigation* 

 Though some water so used has been found to 

 contain scarcely a trace of ammonia, it con- 

 tained nitrates ; and these contribute like am- 

 monia — and more even than that — to the pro- 

 duction of vegetable tissue, or the healthy 

 growth of plants. To this solution of nitrates 

 in some waters, may be owing, in some mea- 

 sure, the fertility of irrigated meadows. 



In concluding this much abridged summary 

 of the memoir submitted by M. Boussingault 

 to the Academy of Sciences in Paris, we give 

 his closing paragraph in his own words, thus 

 translated : — " Notwithstanding the power 

 with which a nitrate acts, we cannot accept it 

 as a manure, as it only contains nitrogen and 

 an alkali; but in associating it w r ith the phos- 

 phate of lime, we obtain truly a compound pos- 

 sessing the qualities of guano, with more per- 

 manence in the nitrogen. In effect on the one 

 hand, guano consists essentially of an intimate 

 mixture of the salts of ammonia and the phos- 

 phate of lime, in a state of nearly equal chem- 

 ical divisions; while, on the other hand, it fol- 

 lows from the foregoing experiments that the 

 alkaline nitrates act on plants in a manner 

 similar to the salts of ammonia. In the coun- 

 try I intend trying, in field cultivation, a mix- 

 ture of nitrate of soda and phosphate of lime 

 in chemical proportions. When these experi- 

 ments are finished, I will communicate the re- 

 sults to the Academy." 



These promised experiments are probably in 

 progress during the present season. The re- 

 sults we shall be pleased to see, and to commu- 

 nicate to our readers. 



Steam Cultivation. 



The cultivation of the soil by the power *of 

 steam, instead of by animals, is a question 

 which has forced itself upon the attention of 

 our farmers in the Western States, wdiere there 

 are broad prairies and very large farms. This 

 subject is one of great and growing import- 

 ance, so much so that Mr. Bronson Murray, of 

 Illinois, as set forth in previous numbers of the 

 Scientific American, has advjsed his brother 

 farmers to contribute and offer a reward of 

 $50,000 for a practical steam plow that will 

 prepare the soil more rapidly, even if the cost 

 of plowing should be equally as great as by 

 horses, the saving of time being the grand ob- 

 ject where spring weather is of short duration. 

 In hilly regions and for small farms the steam 

 plow is out of the question ; it can never over- 

 come the up hill work in the one case, nor be 

 profitably used on small farms in the other. — 

 But on large farms containing several hundred 

 acres of comparatively level . land — such farms 

 as are very common in Indiana, Illinois, and 

 other States — and where there is plenty of cheap 

 fuel, Ave believe that steam plowing will yet 

 become general. Looking at the question on 

 all sides, we do not see a solitary, objection 



