organic state is found in the fact pointed out by Eggertz and Nilson,
that the ash of muck soils is always richer in sulfuric and phosphoric
acids than the solution obtained therefrom by hydrochloric acid.[348]
In a sample of muck examined by them there was found in the ash 1.46 per
cent SO₃, and in the acid extract only 0.05 per cent SO₃; and in the ash
0.3 per cent P₂O₅, while in the extract only 0.04 per cent P₂O₅.
=529. Combustion of the Humus.=—The percentage composition of the
extracted humus can be determined, after drying to constant weight, by
combustion with copper oxid. There is little use in trying to assign
definite chemical formulas to any of the components of the complex which
we call humus. Some of the supposed formulas have been given on pages 61
and 62.
=530. Ether Extract.=—Most peaty soils, when very dry, are not easily
moistened with water. This is due to a superficial coating of fatty or
resinous bodies which prevents the water from reaching the muck
particles. In such cases water will pass between the particles and
percolate to a considerable depth, but without wetting. This oily matter
can be removed by treating the dry material with ether in any approved
extraction apparatus. For the separation of the more purely fatty
bodies, light petroleum may be used, while the total of such matters is
extractable with sulfuric ether. The extracted bodies should be examined
to determine their nature, whether fatty, resinous, or of other
materials soluble in ether. The quantity of this material in some muck
soils is remarkably high. In a Florida muck, examined in this
laboratory, 18.95 per cent in the air-dried substance, which contained
still 41.83 per cent of water, or about 32.5 per cent of the water-free
material were found to be soluble in ether.
The color of the ether extract may be almost black, showing the
extraction of a part of the humus or coloring matter in the muck. This
extractive coloring matter may also be a partial oxidation product of
the original chlorophyl of the plant.
=531. Further Examination of the Ether Extract.=—The ether extract
should be first treated with petroleum ether, unless this substance be
used first in extraction. Afterwards, it is to be exhausted with strong
alcohol, and the quantities of material soluble in the three reagents
separately determined.
The nitrogen is further to be determined in the several extracts, and,
for control, in the residue of the muck.
The method of procedure practiced in this laboratory is to first extract
the sample with petroleum ether, which will yield any free fat acids,
fats, or oils, waxes, and possibly some resinous matter. A weighed
portion of the sample, about two grams, is extracted quantitively by one
of the methods which will be described in the second volume of this
manual.
From two to five kilograms of the sample are then extracted in bulk for
the purpose of securing a sufficient quantity of the material to use for
further analysis.[349]
In each case the petroleum is followed by pure ether, and in this way
the chlorophyl, resins, etc., are obtained. This extract is examined
also for its several proximate constituents.[350]
The treatment with ether is followed by extraction with absolute alcohol
for the removal of tannins and other glucosides, resins insoluble in
ether, etc., and the extract subjected to the usual examination.[351]
Instead of absolute alcohol a spirit of ninety-five per cent strength,
or even of eighty per cent, may be used. The final residue should be
subjected to the usual determination for nitrogen, volatile matter, ash,
etc., in the manner already described. The large amount of resinous and
other matters soluble in petroleum and ether, which is found in the
Florida muck soils, is probably due to the proximity of pine forests,
the débris of which, sooner or later, find their way to these littoral
deposits. Considerable portions of organic humic acids and even humus
itself, may also be removed by ether and alcohol and in every case
nitrogen should be determined in these extracts.
RARE CONSTITUENTS OF SOILS.
=532. Estimation of Copper.=—The natural occurrence of copper in many
vegetables has acquired additional significance by reason of its
relation to added copper in canned peas and other preserves. Formerly,
copper was not regarded, in any sense, as a plant food. Even now it can
scarcely be considered as more than an accidental and non-essential
constituent of vegetable matter. It is by no means certain, however,
that copper may not be, in some sense, in organic combination, as
phosphorus and sulfur often are. It is said, also, to be found in
certain animal organisms, notably in the oyster. In the estimation of
copper in soils, there is first made a hydrochloric acid solution of the
sample. The solution is treated with well-washed hydrogen sulfid until
well saturated. The precipitate is collected at once on a gooch, and
washed with water containing the precipitating reagent. The filtrate is
dried, gently ignited or roasted, and dissolved in aqua regia. After
evaporating to dryness on a steam-bath, water and hydrochloric acid are
added, and the copper reprecipitated in the manner described above.
If zinc be present in the sample the solution should be made very
strongly acid with hydrochloric before the treatment with hydrogen
sulfid, otherwise some zinc may be carried down with the copper.[352] If
lead be present it is also precipitated with the copper and can be
separated as described below. In the filtrate from the solution in
nitric acid after the second precipitation the copper is precipitated as
hydroxid by potash, collected in a porcelain gooch, dried, ignited, and
weighed as CuO. Or the copper may be secured as sulfate and estimated
electrolytically in the manner described in volume second for the
gravimetric estimation of sugar.
=533. Estimation of Lead.=—If the soil contain lead this metal will be
thrown down with the copper as sulfid in the manner described above. In
this case the mixed sulfids are dissolved in nitric acid, diluted with
water, filtered, and washed. The filtrate is treated with sulfuric acid
in considerable excess, and evaporated until all the nitric acid has
passed off and the sulfuric acid begins to escape. After cooling, water
is added and the lead sulfate collected on a porcelain gooch and washed
with water containing sulfuric acid. Finally it is washed with alcohol,
dried, ignited, and the lead weighed as PbSO₄.
=534. Estimation of Zinc.=—If zinc be present in the hydrochloric acid
extract of a soil it may be estimated as carbonate after freeing it
carefully of iron. The principal part of the iron should first be
separated in the usual way by sodium acetate. In the warm solution (acid
with acetic) the zinc is precipitated by hydrogen sulfid in excess. The
beaker in which the precipitation takes place should be left covered in
a warm place at least twelve hours. After collecting the zinc sulfid on
a filter it is washed with water saturated with hydrogen sulfid. In
order to free the zinc from every trace of iron it is better to dissolve
the precipitate in hot dilute hydrochloric acid and reprecipitate as
above, and, after boiling with some potassium chlorate, saturate it with
ammonia. Any remaining trace of iron is precipitated as ferric hydroxid
while the zinc remains in solution. The ferric hydroxid is separated by
filtration and the filtrate, after acidifying with acetic, is treated
with hydrogen sulfid as above. The zinc sulfid is dissolved again in hot
hydrochloric acid, oxidized with potassium chlorate, the acid almost
neutralized with soda and the zinc precipitated as carbonate with the
sodium salt. After precipitation, the contents of the beaker are boiled
until all free carbon dioxid is expelled, the carbonate collected on a
filter, washed with hot water, dried, ignited, and weighed as ZnO.
=535. Estimation of Boron.=—Boron has been found in the ashes of many
plants and agricultural products. Whether or not it be an essential or
only accidental constituent of plants has not been determined. Its
occurrence in the soil, nevertheless, is a matter which the agricultural
chemist can not overlook. The boron should be dissolved from the soil by
gently heating with dilute nitric acid followed by washing with hot
water. Boiling should be avoided on account of the volatility of boric
acid. In the solution thus obtained, concentrated on a bath at a
moderate temperature to a convenient volume, the boron is to be
estimated by the method given in paragraphs =518= and =519=.
AUTHORITIES CITED IN PART EIGHTH.
Footnote 343:
Bulletin 13, Chemical Division, Department of Agriculture, p. 1021.
Footnote 344:
Sanitary and Technical Examination of Water, p. 60.
Footnote 345:
Bulletin de la Société Chimique, [3], Tomes 11–12, p. 955.
Footnote 346:
Anleitung zur Wissenschaftlichen Bodenuntersuchung, S. 126.
Footnote 347:
Mitteilungen über die Arbeiten der Moor Versuchs-Station in Bremen;
dritter Bericht, S. 540.
Footnote 348:
Biedermann’s Centralblatt, 1889, S. 664.
Footnote 349:
Dragendorff’s Plant Analysis, translation by Greenish, pp. 8, et seq.
Footnote 350:
Vid. op. cit. supra, pp. 31, et seq.
Footnote 351:
Vid. op. cit. 7, pp. 38, et seq.
Footnote 352:
Journal für praktische Chemie, Band 73, S. 241.
NOTE.—On page 557, paragraph =500=, ninth line, read “red-yellow”
instead of “blue.”
INDEX.
A
Absorption, cause in soils, 119
determination, 287
of heat, by soils, 115
water, by soils, determination, 136–143
Acetic acid, solvent for soils, 344
Acid phenyl sulfate, reagent for nitric acid, 554, 555
soluble materials, extraction, 455
Adobe, analyses, 58
soils, 57
Aeolian rocks, 38
Air, absorption, 286
action, 51
Albuminoid ammonia, estimation, 572
Alkali salts, composition, 56
Alkalies and alkaline earths, estimation, 384
Alkaline soils, 53–55
Alumina, estimation, 354, 357, 362
Aluminum, 17
-mercury couple for nitric acid, 542
microchemical examination, 266
Ammonia, determination of free and albuminoid, 570–573
estimation, 448–452
formation in soils, 429
magnesia distillation process, 450
nitrification, 466
production, by microbes, 464
Ammonium chlorid, solvent for soils, 343
Apocrenic acid, 62
Apparatus for soil sampling, 82–86
Aqueous rocks, 32–38
vapor absorption, 283, 284
Armsby, soil absorption, 121
Assimilable phosphoric acid, method of Dyer, 410
Atomic masses, table, 3
Atwater, fish nitrogen, 14
Authorities cited in Part Eighth, 593
Fifth, 300
First, 63, 64
Fourth, 279–281
Second, 93, 94
Seventh, 573–575
Sixth, 456–458
Third, 169, 170
B
Bacteria, action, 50
Barium, 23
microchemical examination, 265
Barus, theory of flocculation, 177–180
Beaker elutriation, comparison with Hilgard’s method, 239
method, comparison with Schloesing’s, 241
Belgian methods for soil extracts, 361–363
Bennigsen, method of silt analysis, 194
Berlin-Schöne method, 194
Bernard, calcimeter, 339
Berthelot and André, determination of residual water, 308
method of water determination, 305
nature of nitrogen in soils, 430–434
odoriferous matters in soils, 97
phosphoric acid in soils, 411
Bigelow, solubility of digestion vessels, 348
Boric acid, 580, 581
Boron, 17
estimation, 593
Boussingault and Lewey, method of determining absorption, 290
method for nitric acid, 524–526
Braun’s separating liquid, 271
Bréon’s method, 272
Brewer, chemical action, 177
Brögger’s apparatus, 276
Brucin, reagent for nitric acid, 557
Bulk analysis, 365–367
C
Calcium, 18
microchemical examination, 264
Caldwell, preliminary treatment of soil samples, 88
Capillary attraction, determination, 145
movement of water, 153
Carbazol, reagent for nitric acid, 548
Carbon, 5
comparison of methods for estimating, 321
dioxid, diffusion in soils, 297
estimation in water, 579
in soils, apparatus for estimating, 293
occurrence in soils, 289
solvent for soils, 343
estimation of organic, 315
oxidation with chromic acid, 316
permanganate, 318
Carbonates, Belgian method, 342
deficiency in soils, 340
estimation, 337
Carnot, method for manganese, 397
phosphoric acid, 403
Chabrier, method for nitrous acid, 565
Chemical analysis of soils, 301–575
order of examination, 302
preliminary considerations, 301
elements in soils, 2
Chevreul, ammonium phosphate in guanos, 7
Chile, nitrate deposits, 15, 16
Chlorin, 6
estimation, 422
in water, 577
Mohr’s method, 424
Petermann’s method, 424
Wolff’s method, 423
Citric acid, solvent for soils, 344
Clarke, relative abundance of elements, 23
Classification of soils, 52
Clay, chemical nature, 232
colloidal, 231
mechanical determination, 242
properties, 223
separation, 230
suspension, 176
Clayey soils, effect of boiling on texture, 244–246
elutriation, 239
Cleavage of soil particles, 262
Coefficient of evaporation, determination, 144–146
Cohesion and adhesion of soils, 116, 117
Colloidal clay, estimation, 231
Color of rocks, 31
soil, determination, 97
Colorimetric comparison, delicacy, 548, 559
Compact soils, 90
Conductivity of soils, 115
Copper, estimation, 591
-zinc couple for nitric acid, 540, 542
Crenic acid, 61
Crum-Frankland process, 518
Crystal angles, measurement, 259
Culture media, composition, 468, 473, 474, 476, 479, 481, 483, 484, 486
solid, 479, 481
D
Darton, Florida phosphates, 9
Davidson, origin of Florida phosphates, 7
Decay of rocks, 43–52
Deherain, measurement of percolation, 167–169
Desiccator, drying, 309
Devarda’s method for nitric acid, 534
variation of Stoklassa, 535
Diffusion of gases, general conclusions, 299
Dietrich’s elutriator, 209
Digestion of soil, 456
vessels, 347
Dilution method, experiments, 483, 485
Diphenylimid, reagent for nitric acid, 549
Diphenylamin, reagent for nitric acid, 553
Distillation, prevention of bumping, 441
Dobeneck, method of determining absorption, 287–290
Drainage, influence on porosity, 132
Durham, clay suspension, 176
Dyer, citric acid solution, 344
Dyer, method for assimilable phosphoric acid, 410
E
Earth worms, action, 49
Eldridge, Florida phosphates, 10
Elements, different, simultaneous estimation, 425
relative abundance, 23
Elutriating tube, 236
Eruptive rocks, 41, 42
Estimation of gases in soils, 282–299
F
Ferric oxid, estimation, 353, 356, 357, 362, 399, 401
Fine soil, capacity for holding water, 135
Fish as fertilizer, 14
Flocculation, 171
effect of chemical action, 177
theory, 177
Floccules, destruction, 175
Florida phosphates, origin, 7–12
Fluorin, 17–24
Forchhammer, agricultural value of fucoids, 13
Frear, method of determining soil temperatures, 111
Freezing and thawing, 44
Fuchs and De Launy, origin of potash deposits, 21
Fuelling, determination of water absorption, 139
G
Gases, collection, 291
methods of study, 283
passage through the soil, 149, 150
determination, 150
relation to soil composition, 282
Gasparin, method of silt analysis, 195
Gautier, occurrence of oldest phosphates, 7
Gelatin, culture, 471–473
mineral, 473, 474
Gembloux station, method of soil solution, 350
German experiment stations, method of soil solution, 349
Glaciers, action, 45
Glucinic acid, 62
Goessmann, analysis of sea-weeds, 13
Gooch and Gruener, method for nitric acid, 546
estimation of boric acid, 580
Goss, method for phosphoric acid, 416–418
Grandeau, method of estimating humus, 324
H
Hands, sterilization, 489
Hannén, diffusion of carbon dioxid in soils, 297
Harada’s apparatus, 275
Heinrich, determination of passage of gases through soils, 150
water absorption, 143
method of determining cohesion, 116, 117
Henrici, determination of water capacity of soils, 143
Hilgard, alkaline soils, 55
digestion vessels, 347
humus estimation, 324
hygroscopic coefficient, 284
influence of surface tension, 174
method for soil solution, 348
of silt analysis, 225
methods of analysis of soil extract, 356–361
preliminary examination of soils, 87
Hilgard’s elutriator, 226
method, comparison with Osborne’s, 239
Hooker’s method for nitric acid, 548
Humic acid, 61, 62
estimation, 331
Humus, 60
combustion, 589
estimation, 324
German method, 333
method of Pasturel, 336
Raulin, 334
Van Bemmelén, 332
summary of results, 330
mineral contents, 589
Huston and McBride, humus estimation, 326
method of determining soil absorption, 128
Hydrochloric acid, solvent for soils, 344
strength, 345
time of digestion, 345
treatment of soil with cold, 350
Hydrofluoric acid, solvent for soils, 352
Hydrogen, 5
estimation of organic, 323
Hygroscopic coefficient, determination, 284
I
Ignition, loss, 307
Ilosvay, nessler reagent, 573
Indiana, lysimeter of agricultural experiment station, 165
Indigo method for nitric acid, 524–531
Insoluble residue, analysis, 363
Belgian method, 364
Wolff’s method, 363
Interstitial space, determination, 134
Inverse capillarity, 146
Iron, 22
and alumina, separation from phosphoric acid, 414
French method, 399, 400
method of Sachsse and Becker, 401–403
microchemical examination, 266
J
Jenkins, analysis of sea-weeds, 13
Johnson, method for nitric acid, 556
K
Kaolin, estimation, 426–428
Kedzie, digestion vessels, 347
influence of drainage, 132
King, apparatus for soil sampling, 82
capillary movement of water, 153
methods of water movement, 151
Knop, method of determining soil absorption, 128
Knop’s silt cylinder, 189
Knorr, apparatus for carbon dioxid, 337
Kostytchoff, origin of humus, 60
Kühn’s silt cylinder, 189
L
Lateral capillary flow, 153
Latitude, effect on decay of rocks, 46
Lead, estimation, 592
Lime, assimilable, 392
estimation, 354, 357, 362, 365, 384, 386, 388–394
of active, 389
available, 390
French method, 386, 388
method of Halle station, 393, 394
Russian method, 391
Lithium, microchemical examination, 264
Logarithmic constants, 254
Loges, humus estimation, 333
Loose soils, 89
Loughridge, time of digestion, 345, 346
Lunge and Lwoff, method for nitrous acid, 563
Lunge’s nitrometer, 519
improved, 520–524
Lysimetry, 158, 165
Mc
McGowan’s method for nitric acid, 543
M
Magnesia, estimation, 354, 360, 362, 365, 384, 394, 396
method of Halle station, 396
Magnesium, 18
microchemical examination, 264
Magnet, separation of silt particles, 278
Manganese, 23
estimation, 354, 360, 396, 397
French method, 397–399
Marx, method for nitric acid, 526–528
Masure’s silt apparatus, 210
Matiére noire, 324
Mayer, determination of water absorption, 138
Mayer’s modification of Schöne’s method, 220
Mechanical analysis of soils, 171–179
Mercury and sulfuric acid method, Noyes’ modification, 519
Warington’s modification, 518
Metamorphic rocks, 39
Metaphenylenediamin, reagent for nitrous acid, 557, 559
Microchemical examination of silt, 262, 266
Microscopic apparatus, 495
examination of silt separates, 256
Microscopical structure of rocks, 28, 29
Mineralogical examination of silt separates, 254–278
Minerals, classification, 26
in rocks, 24–26
machine for making sections, 267
Möckern, reduction method, for nitric acid, 533
Moissan, estimation of boric acid, 581
Moisture, effect on soil temperature, 102
estimation, 454
Moore, modification of silt analysis, 192
Muck soils, alcohol extract, 590
estimation of humus, 589
phosphoric acid, 588
sulfur, 587
ether extract, 590
organic carbon and hydrogen, 586
petroleum ether extract, 590
phosphoric acid, 415
sampling, 584
special treatment, 583
total volatile and organic matter, 586
water content, 585
Mulder, humic acid, 62
Müller, method of determining soil absorption, 126
Müntz and Marcano, origin of nitrate deposits, 14
N
Naphthylamin, reagent for nitrous acid, 560
Nessler’s process, 570
reagent, 570
Nitrate deposits, 14–16
Nitrates, estimation, 435
Nitric acid, classification of reduction methods, 531, 532
development in soils, 461
estimation by colorimetric comparison, 548–559
oxidation of a colored solution, 524–531
reduction to ammonia, 531–543
classification of methods, 496–498
in presence of nitrous acid, 557
extraction from soil, 498–500
ferrous salt process, 500–518
iodometric estimation, 543–548
mercury and sulfuric acid method, 518
methods, relative merit, 498
nitric oxid process, 500–524
reduction by electric current, 540–543
solvent for soils, 351
ferment, isolation, 471, 477, 481
Nitrification, apparatus and manipulation, 468
effect of potassium salts, 463
general conclusions, 496
necessary conditions, 461–463
preparation of seed, 468
progress, 469
statement of results, 478
test of commencement, 469
Nitrifying organisms, classification, 487
distribution, 470, 471
microscopic examination, 480, 484
occurrence, 467
Nitrites, destruction, 478, 558
Nitrogen, 12
active soil, 434
Arnold and Wedemeyer’s method, 440
Dumas’ volumetric method, 446–448
economic value, 395
estimation in soils, 428–456
of amid, 451
volatile compounds, 452–454
Hilgard’s method, 436
Methods of Official Agricultural Chemists, 434
Müller’s method 438–440
soda-lime method, 445
nature in soils, 430–434
order of oxidation, 465
organic, in soils, 459–461
oxidized, estimation in soils, 459–570
soda-lime method, 441–444
in presence of nitrates, 444
Nitrous acid, development in soils, 461
estimation, by coloration of a ferrous salt, 567
colorimetric comparison, 559
potassium ferrocyanid, 567
classification of methods, 496–498
iodometric method, 564–567
ferment, isolation, 471, 477
Nöbel’s apparatus, 207
Nöllner, nitrate deposits, 16
Norwacki and Borchardt, auger for soil sampling, 83
O
Odoriferous matters, determination, 98
in soils, 97
Official Agricultural Chemists, latest methods, 454–456
method for reduction of nitric acid, 532, 533
of analysis of soil extract, 353–356
soil solution, 349
Organic matter, estimation, 314
influence on absorption, 124
total, 315
Origin of soils, 43
Orth, classification, 185
Osborne, Berlin-Schöne method, 224
method, comparison with Schloesing’s, 241
of silt analysis, 196
-Schöne method, 219
comparisons, 223
Oxygen, 3
absorption, 286
estimation of organic, 324
P
Packard, separation of silt particles, 273
Pasturel, estimation of humus, 336
Peligot, preliminary treatment of samples, 91
Percolation, measurement, 161
soils _in situ_, 164
Petermann, determination of water absorption, 138
method for phosphoric acid, 409
preliminary treatment of samples, 92
Petrographic examination of silt particles, 266
microscope, 256
Pfaundler, specific heat method, 104–110
Phenylsulfuric acid, reagent for nitric acid, 554
Phosphoric acid, Carnot’s method, 403
estimation, 354, 362, 403–406, 409–416
French method, 406–409
Halle method, 404, 405
in muck soils, 415
method of Goss, 416–418
Hilgard, 413
Petermann’s method, 409
Russian method, 412
separation from iron and alumina, 414
Phosphorus, 6
microchemical examination, 266
state of existence in soils, 411
Piccini method for nitric acid, 558
nitrous acid, 567
Pillitz and Zalomanoff, method of determining soil absorption, 125
Pissis, nitrate deposits, 16
Polarized light, examination, 261
Porosity, 131
determination, 133
Potash, condition in soils, 367
estimation, 355, 358, 361, 365, 368, 370–372, 375–378, 381, 382
international method, 381
Italian method, 377
method of German experiment stations, 375
Tatlock and Dyer, 382
Russian method, 376
salts, deposits, 20
Smith’s method, 378–381
soluble in cold dilute acid, 370
concentrated acids, 368
Potassium, 18
microchemical examination, 263
Pratt, bowlder phosphates, 9
Q
Qualities of soils, 52, 53
R
Rain water, method of collecting, 569
preparation for analysis, 569
Raulin, method of estimating humus, 334
potash, 375
Reaction of a soil, 303
Refractive index, determination, 259
Rideal, method for nitric acid, 553
Rocks, aeolian, 38
aqueous, 32
chemical composition, 30
color, 31
composition, 43
decay, 43–52
eruptive, 41–42
kinds, 32
metamorphic, 39
microscopical structure, 28
minerals, 24–26
sedimentary, 35
types, 28
Rohrbach’s solution, 271