Natural History. 39 1 



course, soon cut very deep channels in the ice. When they 

 reached the river, the troughs were removed a few feet, and thus 

 the streams produced the effect of a saw, which, dividing the ice, 

 forced the portion between them to fall into the Dranse. 



When the weather is fine, these streams, which are not more 

 than four or five inches in diameter, act with extraordinary 

 power, piercing a hole 200 feet deep and six feet in diameter in 

 24 hours. They are calculated to remove one hundred thou- 

 sand cubical feet of ice from the barrier daily, and it is sup- 

 posed that, if the weather is fine, the whole will be removed in 

 three years. 



At the end of the season of 1822, the Dranse remained 

 covered only for a length of 80 toises (of six feet), whereas at 

 the commencement of the operation it was covered over a length 

 of 225 toises. M. Venetz estimates the quantity of ice, removed 

 in 1 822, as between eleven and twelve millions of cubical feet. — 

 Bib. Univer. xxii. 58. 



14. On the Theory of Fatting Stars. — M. Bellani, in a mfemoire 

 on the meteors called falling stars, supports the theory that they 

 are formed by the combustion of trains of inflammable gases or 

 vapours in the atmosphere. He thinks that these trains may 

 exist in the higher regions without being dissipated, in conse- 

 quence of the general and perfect tranquillity which may be con- 

 sidered as existing there. He endeavours to combat the diffi- 

 culty which is generally urged to such a theory, of the diminished 

 inflammability of any gaseous or vaporous mixture by expansion, 

 by referring to the vapour of phosphorus, stating, " that phos- 

 phorus becomes luminous, or sufi'ers a slow combustion, at a 

 temperature so much the lower as the quantity of oxygen gas in 

 a determinate space is rendered smaller, either by mixture with 

 other gases, or by rarefaction ;" and then ventures the con- 

 jecture, that there may be other substances, capable by natural 

 operations of being reduced into the state of vapour or gas ; and 

 which, though at common temperature and pressure are not 

 inflammable, may become so by being elevated in the atmo- 

 sphere. — Giornale di Fisica, v. 195. 



15. Preservation of Anatomical Preparations. — Dr. Macart- 

 ney, of Dublin, employs for this purpose a solution of alum and 

 nitre, which preserves the natural appearance of most of the 

 parts of the body much better than spirit of wine, or any other 

 liquid hitherto employed. In order to impregnate entirely ana- 

 tomical preparations, the liquid ought to be renewed from time 

 to time at first. The proportion of the two salts and the strength 

 of the solution should vary according to circumstances. The 

 solution possesses such an antiseptic power that it destroys 

 completely, in a few days, the fator of the most putrid animal 

 substances. — Ann. de Chirn., xxi. 223. 



