922 RHPORT OF COMMISSIONER OF FISH AND FISHERIES. 



tliat I sliould enter into details concerning the one snbstance of all 

 others callable of absorbing most heat in its transference from the liqnid 

 to the gaseous state. All other agents have, in America, practically 

 given way in practice to ammonia, whether as hqnid or aqueous ammonia 

 in the Carre machines, or anhydrous ammonia compressed by mechanical 

 means, used mostly by infringers of the Oh. Tellier patent. 



N.— ON AMMONIA. 



This agent, known to the early alchemists as spiritus salis uHtiw, in the 

 form of carbonate, was procured by Basil Valentine from sal ammoniac by 

 the action of an alkali. Geber first imported sal-armoniacum from Asia 

 to Europe in the seventh century, and, Uke sulphate of ammonia, it was 

 obtained as a deposit in the immediate j)roximity of volcanoes as well 

 as with the boric acid of the Tuscan Marenune. The origin of ammonia 

 from the effete organic matter constantly j)oured off by the excreta of 

 animals, or in the rotting of vegetable matter, explains its uiuversal diffu- 

 sion. Whereas we now obtain ammoniacal liquor, supplying commerce 

 with this article, from gas-works where the remains of extinct i)lants are 

 being burned, centuries since Europe depended on Egypt for the material 

 distilled from the soot of burning camels' dung. Later on, human urine 

 was emi)loyed in Europe ; and before the era of gas-works animal refuse 

 of all kinds, such as hoofs, horns, bones, &c., furnished the spirits of 

 hartshorn, an aqueous solution, named in Latin sjrintus volatUis salis 

 ammoniaci. After Stephen Hales's experiment in 1727 by heating lime 

 with sal-ammoniac, liquid ammonia was obtained which we find Cullen 

 calling the quick-lime spirit of sal ammoniac, and he placed it at the head 

 of the list of agents calculated to depress the thermometer by their 

 volatility. In 1774, Priestley discovered what he called allcaUne air, 

 and BerthoUet, in 1785, determined the nature of the gases composing it 

 by the aid of the electric spark, and found them to be hydrogen and 

 nitrogen. 



Dr. Angus Smith, in a recent article in the Chemical News (July 

 26, 1878), says : "Ammonia must ever be one of the most interesting of 

 chemical substances." 



" It is now many years," says Dr. Smith, " since Liebig first surprised 

 me by saying that iron ores and aluminous earths were cai)able of tak- 

 ing up ammonia, and if they were breathed upon we were able even to 

 smell that substance." . . . "If you pick \ip a stone in a city, and 

 wash off the matter on the surface, you will find the water to contain 

 ammonia. If you wash a chair or a table, or anything in a room, you 

 will find ammonia in the washing; and if you wash your hands you 

 will find tlie same ; and your paper, your pen, your table-cloth, and 

 clothes all show ammonia; and even the glass cover to an ornament has 

 retained some on its surface. You will find it not to be a jiermanent 

 part of the glass, because you require only to wash with pure water once 



