242 M. Melloni on the Cause of the speedy Melthig 



tab. aen. {ejffig. Ch. Knape in nummo). (63.) Index numismatum in viroruni 

 de rebus medicis vel physicis meritorum memoriam percussorwn. (Physiophili Ger- 

 manid gratul. diem semisecularem, J. F. Blumenbach). Berolini, 1825, {ed. II.) 

 cum. 1. tab. aen: {ejffig. J. F. Blumenbach in nummo.) (64.) Rencentioris eevi 

 numismata virorum de rebus medicis et physicis ineritorum memoriam .^ervantia col- 

 legit et recensuit. Berolini, 1829, (ed. III.) (65.) Poems. Berlin and Greifs- 

 wald, 1798. 



Observations upon the Cause which produces the speedy Melting 

 of Snow around Plants, By M. Macedoine Melloni.* 



I\' one of the last numbers of the Annals of Science of Lom- 

 bardy, we find some extended remarks concerning the greater 

 or less rapidity of the melting of snow in the country, accord- 

 ing to its position, as around trees and bushes, or in open fields, 

 under long herbage, or where dry leaves and other bodies may 

 be placed immediately over it, or suspended at a certain distance 

 above it. The author of these observations, M. Ambroise Fu- 

 sinieri, alleges that many of the phenomena are quite opposed 

 to the consequences which should result from the laws of ra- 

 diated heat, as understood by philosophers.f This opinion may 

 perhaps be true, if the results of my experiments upon the dif- 

 ferent kinds of heat are disregarded ; but if these be adopted, 

 the objections of M. Fusinieri fall to the ground of themselves, 

 and the explication of the observed phenomena becomes nothing 

 more than a simple and pure application of the properties of 

 radiated heat as now established. 



We shall first attend to the observations and reasonings of 

 the author : and, that I may present them as distinctly as pos- 

 sible, I shall take from them every thing that is extraneous to 

 the subject now especially before us, and shall present them in 

 the order which to me appears the most natural. 



In attentively examining what occurs around plants in a hard 

 winter, we readily perceive that the snoW which is placed near 

 the trunks of trees and tufts of bushes, melts more quickly than 

 at a certain distance, so that there is speedily formed around 

 these bodies, in the bed of snow which covers the earth, exca- 



* Bibliotheque Universelle, June 1838. 



t Annali delle Scienze del rcnino Lombardo-Veneto, Opera periodica di 

 Alcuni Collaboratori, Gen. et Feb. 1838, p. 38. 



