A M M

A jVT M

( 49 )

useful. Mr. Phillips has the following ex-periment. a To 9 ox. of ii.ne slacked withhalf a pint of water, and put in a closedvessel, were added 12 oi. of muriat of am-monia, and 3 \ pints of boiling water. Themixture having cooled, the clear solution wasdivided into two equal portions and separately-distilled, without putting any water in thereceiver or employing pressure. Ten ouncemeasures of distilled liquor of ammonia wereobtained from each portion, of the specificgravity of .954, which according to Davy ’stables indicates about ill per cent, in weightof the pure alkali. The quantity of lime hereused is amply sufficient, indeed the same weightas the muriat of ammonia would be sufficient,if the lime is made from marble or any purelimestone, and thoroughly well burnt.

Mr. Dalton k has given a table of the strengthof ammoniacal solutions somewhat differingfrom that of Davy . The data which Mr.Dalton assumes, (from particulars which neednot be here enlarged upon) and on which theaccuracy of the table depends, are the following:

100. water-grain measures of liquid muriaticacid of 1.074 sp. gr. contain 11. grains of realacid : the specific gravities of muriatic acid gasand ammoniacal gas are in the respective pro-portions of 1.23 and 0.6 and 11. measures ofthe acid gas saturated 12. measures of theammoniacal g?.s. No allowance is requiredfor condensation in constructing the followingtable, it having been found both by Davy and Mr. Dalton, that when liquid ammonia ismixed with water, the specific gravity is asnearly as possible the mean of the two. Mr.Dalton’s table is the following.

Grains of ammonia

Grains of

Specific

in 100 water-

ammonia

gravity.

grain measures

in 100 grains

of liquid.

Of the liquid.

.8.5

30.

35.3

.86

28.

32.6

.87

26.

29.9

.88

24.

27.3

.89

22.

24.7

.90

20.

22.2

.91

IS.

19.8

.92

16.

17.4

.93

14.

15.1

.94

12.

12.8

.95 '

10.

10.5

.96

8.

S.3

.97

6.

6.2

.98

4.

4.1

.99

2.

2.0

Analysis of ^.m mania.

In the article Ammonia (Chem. Diet .) wementioned the experiments of Priestley, Ber-thollet, and other chemists, which shewed thisalkali to consist of azote and hydrogen, in theproportions of about 4 parts by weight of theformer, and J part of the latter. A numberof important researches have since been madeby several eminent chemists, which require adetailed notice.

The fixed alkalies being proved by Davy to be compounds of a peculiar metallic baseand oxygen, it naturally occurred to this emi-nent philosopher that the analogy with theother alkalies would infer a similar compositionin the volatile alkali, which however seemedto be contradicted by the experiments of Ber-thollet and Sir H. Davy himself, in which am-monia was wholly resolved into azote andhydrogen, unless either of these latter sub-stances was itself an oxyd of some unknownbase.

A very laborious series of experiments onthe analysis of ammonia by electricity and com-bustion with oxygen and other gasses, has beenpublished by Dr. Henry, c which we shalldetail somewhat at large, on account of thegreat importance of the subject, the admirablepractical skill and ingenuity with which theexperiments were carried on, and the clearidea which it gives of the extreme difficultywhich exists in obtaining perfectly accurateresults in these deiicate operations, from avariety of causes that are here explained.

The first object is the apparatus. Dr. H.found in former experiments that in the usualway of electrizing gasses, a temporary com-munication is made with the atmosphere atthe moment of the explosion, which in thecourse of a long experiment is sufficient tointroduce so much atmospherical air, as sen-sibly to affect the result. The only unobjec-tionable way, as Dr. H. mentions, is to incloseand hermetically seal the explosion wires inglass tubes, and then to grind away so muckof the glass as will expose the ends of thewires. Those employed in these experiments'were of platina, ^ of an inch in diameter.

The next and most difficult'object is to freethe ammoniacal gas entirely from water. Theavidity with which this gas retains moistureis very remarkable. A confined quantity ofcommon air may be so completely desiccatedin a few minutes by pure dry potash or drymuriat of lime, that no ice shall appear on the

* Examinat. of the Pharm, Load. 1811. k New System of Chemical Philosophy, vol. 2d. • Philos. Trans, for 1809,

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