66 Odour of Roses increased by Onions. 



with eminent success by Dr. Carmichael Smyth. We certainly 

 know that vegetation wears a greener hvery, and healthier 

 aspect, after the thunder-storm, which, in its meteorological 

 character, serves obviously to restore the balance of tempera- 

 ture, and promote an equable distribution of moisture ; and its 

 effects in relation to vegetation may not so much depend on 

 its electric affinity with the circulation of the sap in vegetation, 

 as on the evolution of nitrous acid gas in the atmosphere, in the 

 decomposition of miasmata, or aerial poisons, hurtful to, or 

 destructive of vegetation, and healing abraded and decaying 

 surfaces ; perhaps, too, destructive to animalculse, &c., as 

 the Coccus, A phis, &c., which prey on the vital juices of the 

 plant, and " drink its marrow up." In exotic vegetation, 

 limited to the precincts of the stove or conservatory, and then- 

 stagnant and imprisoned atmosphere (for ventilation is too litde 

 reglirded), it is highly worthy of experiment how far a small 

 pm-tion of nitrous acid gas, liberated cautiously by the action 

 of sulphuric acid or nitre, might be serviceable in promoting 

 a healthy vegetation, and restoring unhealthy vegetation to its 

 proper tone. We may thus gain a powerful auxiliary and 

 active agent, and the consequence would be a beauteous and 

 luxuriant vegetation, " bearing its blushing honours thick upon 

 it." By a careful inspection of what occurs around us, we 

 occasionally glean valuable practical hints ; and an inspection 

 of the wondei-s of the thunder-storm may be rewarded by the 

 fruits of a successful application of the produce of its power. 

 — Jolm Murray. 



An Onion planted near a Rose said to increase its Odour. — 

 This remark has already appeared in the Gardener's Maga- 

 zine, and I think the experiment is one that promises success. 

 I was led, some time ago, to submit the onion to chemical 

 analysis, when I discovered that it contained much ammonia. 

 Mons. Robiquet, of Paris, some years ago proved that ammonia 

 possessed the peculiar property of restoring the lost aroma, as 

 in musk, &c. ; and I am also of opinion it is the efficient cause 

 in the developement of the aroma in flowers ; and that night- 

 smelling plants, as the Geranium triste, jRosa odora, &c., are 

 indebted for this very peculiar featui'e in their physiology to 

 ammoniacal gas, liberated at this season of repose, and at no 

 other period of the day. What effect the cautious adminis- 

 tration of a solution of carbonate of ammonia to sweet-scented 

 flowers, in the form of a gentle waterhig occasionally, may 

 produce, experiments can alone determine. When rose 

 leaves, &c. are preserved in perfume-jars, common salt is gene- 

 rally sprinkled over them. A little powdered carbonate of am- 

 monia 1 find increases the aroma. — Id. 



