'. Chemical and Economical FaBs, 71 



IV. 



Ohfervat'tons Chemical and Economical on various SubjeEls *. 



i.iVI. TROMSDORFF, Profeflbr at Erfart.has obferved that fulphurated hydrogenoUi 

 gas takes fire and burns with a ftrong flame by means of the nitrous acid. 



2. M. Linck, ProfefTor at Roftoc, finds that three parts of nitrous gas, and two of hydl-b- 

 genc gas, obtained by fulphuric acid and iron, are fcarcely or not at all diminifhed when 

 cxpofed to day-light over water. Common air is not more diminifhed by this admixture 

 kept a long time : but the mixture itfelf of thefe two gafes is diminifhed by the addition 

 of new portions of nitrous gas. M. Linck concludes from this obfervation, that part of 

 the oxygene of the nitrous gas combined with the hydrogenc and formed water, and that 

 the remaining oxygene and azote formed a mixture fimilar to the air of the atmofphere. 



Citizen Vauouelin made a (imilar remark ten years ago on nitrous gas placed over a folii- 

 tion of the hydro-fulphuret of lime. The diminution of the gas was confiderable. 



3. The urine of animals which feed on vegetables does not contain phofphoric acid, but 

 an acid of a vegetable nature. On this paflage C Vauquelin remarks, that Rouelle an- 

 nounced this fa£t twenty years ago, and that C. Foiircroy and himfelf have lately proved it 

 by a great number of experiments, which have moreover (hewn that the acid which fup- 

 plies the place of the phofphoric in thefe animals is the benzoic. 



On this occafion it iriay be remarked, that the vegetable kingdom afFords phofphorus ; 

 that the bones which are produced and grow in animals feeding only on vegetable food 

 contain this fubftance ; whence it appears probable that their urine is not at all times di- 

 vefted of phofphoric acid. M. Giobert in his memoir on phofphorus ( Annales de Chimie, 

 adi. 23.) affirms that the urifte of horfes is nearly as proper for his procefs as that of men ; 

 that is to fay, that it affords nearly as much phofphorus. But he does not pofitively relate 

 any experiment to this efFeft. 



4. A German correfpondent of the work before us affirms, that the blowing machines or 

 bellows for the iron works in the Hartz, are cubical boxes of wood, which arc more eafily 

 made than the iron cylinders made ufe of in England, and that they are very advantageous 

 in the ufe. From various accounts there Is reafon to think, that the denfity and velocity 

 of the flream of air from our iron cylinder worked by a fteam engine are greater than has 

 ever been afforded by the wooden bellows or other blowing engines formerly in ufe. The 

 height to which this air will fupport a column of water is between fix and feven feet, or at 

 a medium near fix inches of mercury. 



5. Attempts have been made in Saxony, and particularly at Fr^yberg, to increafe the 

 quantity of water made ufe of to move the machines in that country. It has been found 

 convenient to eflablifh pumps worked by the wind, to ralfe a portion of the water which 

 palfes through the galleries, or is collefted in the works. It is not intended to make ufe of 

 this inconftant firfl riiover to clear the mines of water, but fimply to fill the refervoirs 

 which work the hydraulic machines, at the fame time that the fecoiidary advantage of affift- 

 ing to keep the mines clear Is obtained. By this means the power of the wind, changeable 

 ask is, may be rendered fteadily ufeful. The celebrated Leibnitz firft thought of this con- 



* Journal del Mines, No. 19. 



trivancc» 



