compound Au< 'l.:'N 1 1 .. thus obtained is introduced into ;( bent tube 

 itiu'. I'M. whose open end c i-tlirn fused up. The compound is then 

 slightly heated at it, and the ammonia comes <>\Y. OWJULC t" the easy 

 dissociation of tin 1 compound. The other end of the tube is immersed 

 in a free/ini; mixture. The pressure of tlie --as 



comiii" oil', comltiiied with the lo\v temperature 



. 



^\ at one end of the tube, causes the ammonia 



c<^ ^"^ e\-olved to condense into a liquid, in \vliieli form 



r;,, ;- i ,- it collects at the cold end of the tube. If the 



heating be stopped, the silver chloride a^fain 



absorbs t he ammonia. In this manner, one tube 



" may serve for repeated experiments. Ammonia 



may also be liquefied bv tlie ordinarv methods 



that is. bv means of pumping dry ammonia -ras into a refrigerated 

 space. Jj<|uHifd ammonia is a colourless and very mobile liquid.'* 

 whose specific gravity at 0" is ()(]:} (}]. Andivett'). At the temperature 

 (about 7" ) u'iven b\- a mixture of liquid carbonic anhydride and ether, 

 liquid ammonia crystallises, and in this form its odour is feeble, because 

 at so lo\v a temperature its vapour tension is very inconsiderable 1 . The 

 boil in-- point (at a pressure of TOO mm.) of li(|iiid ammonia is about '\'2 \ 

 Hence tliis temperature may be obtained at the ordinary pressure by 

 tlie e \'apo rat ion of li|iielied ammonin. 



Ammonia. eontaininL! 1 . as it doe>. much h\'dro--(Mi. is fti/Hiri/i J 

 i'i,ni iis/>f,/, ; it does not. however, burn regularly, and sometimes not 

 at all. in the ordinary atmospherie air. In ]>ui'e oxygen it burns with 

 a greenish -yellow llame, 1 " forminu' water, \\'hilst the nitrogen set tree 



. , I ' 



pl'e- I . t ahi Hit -JII ; Cdlisei jllellt I V. at 



the at l i|-< n re. v. hil-t at 1< >Wer telllpel 



l.\ tl e . )hi , ctunptuiml. CMII^JI 



." i i i. \ In l,f nh-erved. 



'' 'I In " if a n i moil ia ma v he acci miplishetl \\ ill milt an increase <(' pressure 



' ' .; a Mint i\e pi i We r FI .I 1 eifjillfv ft -rill- a prnhlem which ha-, to II 



extent In i .etlhv the Kr, |,cl, , M |-i 1 1 e, r T. I . 



The , la a ill I,.- ell Ilia \ In etTei let] l.\ t he iliil ni phi t illlllll. 



p, , ecket! heaker ,,j ;il<lll I. Ill' lit I'. Cllpacil \ . A -as < .lllrtilr: tllhe 



I ,,,:,' 1 n I p] , . . . . i] ill 1 In iitplei HI- -nlllt inll nf 



! : tin i i |e, cent platinum -pira 1 :- placet! in 



(.lie 1 iea hi ; t ! I |e pre-e|ice i i) t 1 ] e p 1 i t i 1 1 1 1 ! 1 1 i - i i X 1 1 I 1 ~et 1 a 1 1 1 1 1 1 1 1 r 11 . U 1 1 I I - 1 



the plal .1 m.-iv incamle cent. The iinnmiiiia i- then heatetl. ami 



t: I eil I., th. . Illtit ''. The , .;... II, a it hllhhle- ,,11 fr..]|| the illllllllllliil 



int.. r.nit.ict v.ith lli. . -.en! plal inn. Tin i I'. .!! .\\ i-i| I,;, a . ertain c. > ilimj efTect, 



