THE AMMONIA OF THE SOIL. Q49 
The fact that caustic potash, a more energetic decom- 
posing agent than lime, disengaged more ammonia than 
the latter from the yellow clay, strengthens the view that 
ammonia is produced and not merely driven off under the 
conditions of these experiments, and that accordingly the 
figures are too high. Other chemists employing the same 
method have obtained similar results. 
Boussingault (Agronomie, T. ILI, p. 206) -was the first 
to substitute magnesia for potash and lime in the estima- 
tion of ammonia, having first demonstrated that this sub- 
stance, so feebly alkaline, does not perceptibly decompose 
gelatine, albumin, or asparagine, all of which bodies, espe- 
cially the latter, give ammonia when boiled with milk of 
lime or solutions of potash. The results of Boussingault 
here follow. , 
Localities. Quantity of Ammonia per cent. 
Liebfrauenberg, JRISHIIA™ ie atee oe sroten Sate ec oo ets 0.0022 
Bischwiller, Seep eee EL are ck AB as 0.0020 
Merckwiller, i i Pte eee ne te Ay wae 2 O0012 
Bechelbronn, ee dhs Maite a cian art iwi) ti Sarai alo see a rere = 0.0009 
Mittelhausbergen, ogee Teas aes eS. 2 aboot eet 0.0007 
HemNapolcan. Mnlhouses 3) e's 6.2 esas tos so eede eee eoe ek ce 0.0006 
RPP CMTE CIUTIG LS wy ges Wie fy vasarstnsie omc oiascintr einicesinia qeivis wise 0.0060 
Gucsnoy-sur-Dewles Nord, § Pits es sir. eb clos ails «dine See 2 0.0012 
Rio Madeira, Ameneae 4S doin. Seutocteeeaie ne den es 0.0090 
Rio Trombetto, MS ee eae Se tuid acinar aot ema ee ee 0.0030 
Rio Negro, os Oe MO fm 6 eee bak Oe Reda eC ae 0.0038 
Santarem, ee eee et ee aoe Meer 0.0083 
Tle du Salut, Teo, Ligue love bapalelatac Saxe bow Slava lerstseotssiene orate 0.0080 
Martinique, Seni tRa le ate tanec Strats ches See 0.0085 
ro oupart, (ert mold.) °° 7, us tade Seco hex chee ocatek's 0.0525 
Peat, API Gter CR ls eos cea a neo oe ee 0.0180 
The above results on French soils correspond with those 
obtained more recently on soils of Saxony by Knop and 
Wolff, who have devised an ingenious method of estimat- 
ing ammonia, which is founded on altogether a different 
principle. Knop and Wolff measure the nitrogen gas 
which is set free by the action of chloride of soda (Ja- 
velle water*) in a specially constructed apparatus, the 
* More properly hypochlorite of soda, which is used in mixture with bromine © 
and caustic soda. 
lif 
