SO^ Continuation of Lucas's Experimeyits 



deal of oxygen, which facilitates germination, and which can 

 immediately penetrate the seed, •i. Snow being a loose cover- 

 ing and a porous body, does not prevent the admission of air to 

 the seed, and is, therefore, a powerful agent in promoting ger- 

 mination. 



I need hardly mention that as there is a powerful excitement 

 of the vital principal of the seed, a temperature of at least 

 12° Reaumur {59° Fahr.), even for alpine plants, is absolutely 

 necessary; because, if the seed is in a colder temperature, it 

 will not germinate, but on the contrary will ferment, and the 

 snow water will penetrate into the seed and swell it out to double 

 the size. 



[Further results will be given in a future Number.] 



Art. III. Continuation of the Experiments of the Effects of Char- 

 coal on Vegetation, made in the Royal Botanic Garden of Munich. 

 Bv M. Edward Lucas, formerly in the Munich Botanic Garden, 

 and now Botanic Gardener at Ratisbon. 



(From the Garten Zeitung for 1841, p. 25.) 



Encouraged by the universal interest which the application of 

 charcoal in the cultivation of plants has awakened, I venture to 

 lay before the reader the result of continued observations and 

 experiments. This subject excited much curiosity in the course 

 of the year ; mention was made of it in a great number of papers, 

 and experiments set on foot in many gardens of which I was an 

 eye-witness. Success did not always equal the expectations 

 formed of it; a circumstance, however, which is no disparage- 

 ment to the efficacy of charcoal ; for, in every case, either the 

 manner of applying it, or the quality of the charcoal itself, was 

 the cause of failure. In consequence of this, charcoal lost its 

 repute in many gardens, while in others, where at first no ex- 

 periments succeeded, it is, by persevering in the treatment, now 

 applied to most sorts of plants. By some I was not sufficiently 

 understood, particularly in my remarks on the moisture neces- 

 sary for the charcoal, and hence the complaint that every thing 

 damped off. I confess that I have spoken too loosely on this 

 head, and, perhaps, have said too much ; as in many cases, and 

 particulai-ly when used in pots, as soon as the capillary fibres of 

 the charcoal are full, a superfluity of water would be useless or 

 even injurious to the plants; when mixed with the soil, however, 

 it requires more frequent watering than would otherwise be 

 necessary. The chief cause of failure arose from having the 

 charcoal too finely pulverised ; by which its chief properties, ca- 

 pillarity, capability of condensing gases, and porosity, were lost. 

 I was also reproached with having brought forward so old a 

 subject ; to this I reply that to me and to most lovers of plants 



