] 76 Miscellanies. 



Having been presented, by my friends in Paris, with a few Chinese 

 n:iulberry trees, Morus muMcaulis, intended by me to be immediately 

 propagated, I have been able, through the skill of an excellent gar- 

 dener, to obtain, in four months, no less than seven trees from two 

 only, in perfect and full growth. Nothing is more astonishing than 

 the success with which that plant can be propagated. Its leaves are 

 twelve inches long and nine or ten wide, and absolutely thin and fine. 

 Before the opening of the winter, I hope to be able to present one 

 to every agricultural institution of the country. With this it is no long- 

 er problematic that two crops of silk can be obtained in one season. 



19. Protection for Steam Boilers. — Dr. Comstock, of Lebanon, 

 Conn., in a letter to the Editor, suggests the plan of incasing the 

 whole boiler with timber, placed at a proper distance ; the thought 

 is a good one, but in our judgment no plan will answer which does 

 not remove the boiler out of the frequented part of the boat ; and in 

 two articles in the present number, we have suggested a plan which 

 we conceive would obviate, in a great degree, the mischief arising 

 from the explosion of boilers on board of steam boats. 



JVotices Translated and Extracted by Prof. Ghrlscom. 



CHEMISTRY. 



1 . Sulphuric acid produced by the vapors of the Aix waters. — 

 The hot mineral waters of Aix, in Savoy are two in number, and 

 are distinguished, one as the aluminous, the other as the sulphuretted. 

 It has frequently been stated that the vapours of the former contain- 

 ed free sulphuric acid. That they produce sulphuric acid, is proved 

 by the following observations of Mr. Francoeur. First, All the 

 grottoes, closed chambers, corridors, &.c. ; where the vapours pene- 

 trate, have their walls corroded and covered with acid crystals of 

 sulphate of lime. Secondly, All iron utensils, Stc. are not only cor- 

 roded, but are often found encrusted with sulphates of iron and lime. 

 Thirdly, Tubes of cloth, through which the vapors are passed, are 

 quickly rotted, and the rags are found impregnated with sulphuric 

 acid. No free sulphuric acid exists in the water itself, and from the 

 circumstances, it follows that the mixture arising as vapor, and con- 

 taining hydrogen, azote, sulphur, and carbonic acid, has the power 

 of producing sulphuric acid by means of the atmosphere, and in 

 contact with the walls and metals. — Annales des Mines. 



