1822.] Scientific Intelligence, 393 



VI. Arseniuretted Hydrogen Gas, 



M. Serrulas proposes the following method of preparing this gas, 

 A mixture is to be made of two parts of antimony, two parts of bi- 

 tartrate of potash, and one part of arsenious acid, they are to be 

 well triturated together in a mortar, and heated strongly for two hours 

 in a close crucible. The alloy which results, when in contact with 

 water, produces hydrogen gas, saturated with arsenic, and it may be 

 preserved for any length of time in close vessels : to obtain the gas, 

 about 150 grains, reduced to coarse powder, are to be put quickly 

 under a jar filled with water, and inverted in a glass basin containing 

 water. Many cubic inches of arseniuretted hydrogen gas will be ob- 

 tained in a few minutes. — (Journal de Physique.) 



VII. Analysis of the Roots of Black Hellebore. 



M. M. Feneulle and Capron have lately analysed the roots of 

 black hellebore. The products which they obtained were : — 1 . A vo- 

 latile oil; 2. A fatty matter; 3. A resinous matter ; 4<. Wax; 5. A 

 volatile acid; 6. A bitter principle ; 7. Mucus; 8. Alumina; 9. Gal- 

 late of potash, and acidulous gallate of lime ; 10. A salt, with an 

 ammoniacal base. 



VIII. Heavy Spar. 



Stromeyer has published an analysis of the heavy spar of Nutfield, 

 in Surrey, from which it appears, that it contains no sulphate of 

 strontian ; and further, that the proportions of the earth and acid are 

 nearly the same as in the artificial sulphate of barytes. This latter 

 fact, Stromeyer remarks, is of importance, from its showing that the 

 natural combinations of bodies are constituted according to the same 

 fixed proportions as those which are formed artificially. — (Edin. Phil, 

 Journal.) 



It has surely been long known that the composition of artificial 

 sulphates, carbonates, &c. is similar to the natural. — Ed. 



IX. Slide of Alpnach, 



M. Rupp, a skilful engineer, of Wirtemberg, constructed some 

 years ago a slide for the purpose of conveying fir trees from the forest 

 of Mont Pilate, near Lucerne, into the lake of that name. The 

 distance which they had to be conveyed is about 46,000 feet. The 

 medium height of the forest is about 2500 feet. The horizontal 

 distance, when reduced to English measure, is about eight miles. The 

 declivity is one foot in 17'68; the medium angle of elevation 

 3° 14' 20". This declivity, though so moderate on the whole, is in 

 many places very rapid ; at the beginning of the inclination it is about 

 one-fourth of a right angle, or about 22° 30', in many places it is 20^, 

 but no where greater than 22° 30'. 



Along this line the trees descend, in a sort of trough, built in a 

 cradle form, and extending from the forest to the edge of the lake. 

 Three trees squared and laid side by side form the bottom of the 

 trough ; the tree in the middle having its surface hollowed, so that a 

 rill of water, received from distance to distance over the side of the 

 trough, may be conveyed along the bottom and preserve it moist. 

 The trees which descend by this conveyance are spruce firs, very 

 straight, and of great size. All their branches are lopped ofi"; they 



