184 SUGGESTIONS FOR NEW EXPERIMENTS. 



the view of throwing light on this theoretical question, small 

 experiments might be made with it upon different plants with- 

 out incurring any serious expense. It is not unlikely that, by 

 such experiments, light may be thrown on the differences 

 observed in the comparative actions of the nitrates and the salts 

 of ammonia in similar circumstances. 



10. Their special and precise effects on the blossoming of 

 flowers is an interesting subject of inquiry. When flower-buds 

 are plucked and waxed up so as to prevent their opening, they 

 may, a week after, be made to blossom by removing the wax, 

 and placing the stems in a solution of nitre. Is there any 

 specially useful action exercised by the nitrates over plants at 

 the season of blossoming? Is there any connexion between 

 such action and the nitrogen which flower-leaves are said to 

 give off in the daytime ? 



11. Will the more succulent nitrated grass even though it 

 may yield no greater a weight of hay go farther in feeding 

 cattle than the less bulky unnitrated grass from the same field ? 



12. And this leads to certain purely chemical, though most 

 important, practical inquiries, which I only mention here. Is 

 nitrated hay, weight for weight, more nutritive than such as 

 grows naturally, or without any such top-dressing? Does it 

 contain more nitrogen ? Do the seeds of plants wheat, barley, 

 &c. contain a larger percentage of nitrogen when they have 

 been dressed with any of these nitrates ? Are turnips, or beets, 

 or cabbage more nutritive ? These questions are very import- 

 ant. I shall revert to them again, when, in a subsequent 

 chapter, I come to enumerate the various theoretical and prac- 

 tical questions, for the solution of which conjoined researches in 

 the field and in the laboratory are, in the present state of our 

 knowledge, especially required.* 



13. I specially indicate experiments with nitrate of magnesia 

 as desirable, especially upon corn-crops, in the seeds of which 

 magnesia is known to abound. No trials have ever been made 

 with this substance $ and yet with it, as well as with the nitrate 

 of lime, interesting results may be obtained. The equivalent 

 quantity of dry nitrate of magnesia is 93 J. 



* See also Chapter xiii. 2 and 3. 



