AMMONIUM, CHLORIDE OF 149 



the thirteenth to the middle of the seventeenth century, and whence all the European 

 markets were supplied the following is the process by which it is obtained : 



The original source was the urine and dung of the camel, which are dried by plas- 

 tering them upon the walls, and burning, other fuel being very scarce in that country. 

 A fire of this material evolves a thick smoke, charged with chloride of ammonium, 

 part of which is condensed with the soot. 



In every part of Egypt, but especially in the Delta, peasants are seen driving asses 

 loaded with bags of that soot, on their way to the sal-ammoniac works. 



Here it is extracted in the following manner : Glass globes, coated with loam, are 

 filled with the soot, pressed down by wooden rammers, a space of only two or three 

 inches being loft vacant, near their mouths. These globes are set in round orifices 

 formed in the ridge of a long vault or largo horizontal furnace flue. Heat is gradu- 

 ally applied by a fire of dry camels' dung, and it is eventually increased till the globes 

 become obscurely red. As the chloride of ammonium is volatile at a temperature 

 much below ignition, it rises out of the soot in vapour, and gets condensed into a 

 cake upon the inner surface of the top of the globe. A considerable portion, how- 

 ever, escapes into the air ; and another portion concretes in the mouth, which must 

 be cleared from time to time by an iron rod. Towards the end, the obstruction be- 

 comes very troublesome and must be most carefully attended to and obviated, other- 

 wise the globes would explode by the uncondensed vapours. In all cases when the 

 subliming process approaches to a conclusion, the globes crack or split ; and when 

 they come to be removed, after the heat has subsided, they usually fall to pieces. The 

 upper portion of the mass is separated, because to it the white salt adheres ; and, on 

 detaching the pieces of glass with a hatchet, it is ready for the market. At the 

 bottom of each balloon a nucleus of salt remains, surrounded with fixed pulverulent 

 matter. This is reserved, and, after being bruised, is put in along with the charge of 

 soot in a fresh operation. 



The sal-ammoniac obtained by this process is dull, spongy, and of a greyish hue ; 

 but nothing better was for a long period known in commerce. Fifty years ago, it 

 fetched 2s. 6d . a pound ; whereas now, perfectly pure sal-ammoniac may bo had at 

 one-fifth of that price, 



Manufacture of Sal-Ammoniac from Bones and other Animal Matter, Various 

 animal offals develop, during their spontaneous putrefactive fermentation, or their 

 decomposition by heat, a large quantity of free or carbonated ammonia among their 

 volatile products. Upon this principle many sal-ammoniac works have been esta- 

 blished. "Watts's ' Dictionary of Chemistry.' 



The first attempts made in Franco to obtain sal-ammoniac profitably in this manner 

 failed. A very extensive factory of the kind, which experienced the same fate, was 

 under the superintendence of the celebrated Baume. It was established at Gravelle, 

 near Charenton, and caused a loss to the shareholders in the speculation of upwards 

 of 400,000 francs, which result closed the concern in 1787. For 10 years after that 

 event, all the sal-ammoniac consumed in France was imported from foreign countries. 

 Since then the two works of MM. Payen and Pluvinet were mounted, and seem to 

 have been tolerably successful. Coal soot was, prior to the introduction of the gas- 

 works, a good deal used in Great Britain for obtaining sal-ammoniac. 



In France, bones and other animal matters are distilled in large iron retorts for the 

 manufacture of both animal charcoal and sal-ammoniac. 



' The annexed numbers show the produce of a French manufactory of ammonia and 

 its salts, from the distillation of bones and other matters. 



' The materials were 



46,754 tons of bones of various kinds. 

 30 ,, silk waste and old leather. 

 11J- sulphuric acid. 

 80 chloride of sodium. 

 2j sulphate of lime, 

 and the produce was 



2,400 tons of animal charcoal. 

 44 chloride of ammonium. 

 100 ., sulphate of soda. 

 4 ,, liquor ammonia, 

 and 25 sulphate of ammonia.' 



Muspratt. 



These retorts are iron cylinders, two or three feet in diameter and six feet long. 

 Figs. 40 and 41 show the form of the furnace, and the manner in which the cylinders 

 are arranged, the first being a longitudinal, the second a transverse section of it. A, 

 the ashpits under the grates ; u, tho fire-places, arched over at top ; c, tho vault or 



