Part 8
If experiments are made upon gra.s.s or clover, the gravest errors may arise by drawing conclusions from the appearance of the standing crop.
Experience has shown that two clover crops, gathered from contiguous plots differently manured, may strikingly differ in appearance, but yield the same amounts of hay.
The _chemical examination_ of a peat may serve to inform us, without loss of time, upon a number of important points.
To test a peat for _soluble iron salts_ which might render it deleterious, we soak and agitate a handful for some hours, with four or five times its bulk of warm soft water. From a _good fresh-water peat_ we obtain, by this treatment, a yellow liquid, more or less deep in tint, the taste of which is very slight and scarcely definable.
From a _vitriol peat_ we get a dark-brown or black solution, which has a bitter, astringent, metallic or inky taste, like that of copperas.
_Salt peat_ will yield a solution having the taste of salt-brine, unless it contains iron, when the taste of the latter will prevail.
On evaporating the water-solution to dryness and heating strongly in a China cup, a _vitriol peat_ gives off white choking fumes of sulphuric acid, and there remains, after burning, brown-red oxide of iron in the dish.
The above testings are easily conducted by any one, with the ordinary conveniences of the kitchen.
Those that follow, require, for the most part, the chemical laboratory, and the skill of the practised chemist, for satisfactory execution.
Besides testing for soluble iron compounds, as already indicated, the points to be regarded in the chemical examination, are:--
1st. _Water or moisture._--This must be estimated, because it is so variable, and a knowledge of its quant.i.ty is needful, if we will compare together different samples. A weighed amount of the peat is dried for this purpose at 212 F., as long as it suffers loss.
2d. The _proportions of organic matter and ash_ are ascertained by carefully burning a weighed sample of the peat. By this trial we distinguish between peat with 2 to 10 _per cent._ of ash and peaty soil, or mud, containing but a few _per cent._ of organic matter.
This experiment may be made in a rough way, but with sufficient accuracy for common purposes, by burning a few lbs. or ozs. of peat upon a piece of sheet iron, or in a sauce pan, and noting the loss, which includes both _water_ and _organic matter_.
3d. As further regards the organic matters, we ascertain _the extent to which the peaty decomposition has taken place_ by boiling with dilute solution of carbonate of soda. This solvent separates the humic and ulmic acids from the undecomposed vegetable fibers.
For practical purposes this treatment with carbonate of soda may be dispensed with, since the amount of undecomposed fiber is gathered with sufficient accuracy from careful inspection of the peat.
Special examination of the organic acids is of no consequence in the present state of our knowledge.
4th. The _proportion of nitrogen_ is of the first importance to be ascertained. In examinations of 30 samples of peat, I have found the content of nitrogen to range from 0.4 to 2.9 _per cent._, the richest containing seven times as much as the poorest. It is practically a matter of great moment whether, for example, a Peruvian guano contains 16 _per cent._ of nitrogen as it should, or but one-seventh that amount, as it may when grossly adulterated. In the same sense, it is important before making a heavy outlay in excavating and composting peat, to know whether (as regards nitrogen) it belongs to the poorer or richer sorts.
This can only be done by the complicated methods known to the chemist.
5th. The estimation of _ammonia_ (actual or ready-formed,) is a matter of scientific interest, but subordinate in a practical point of view.
6th. _Nitric acid_ and _nitrates_ can scarcely exist in peat except where it is well exposed to the air, in a merely moist but not wet state. Their estimation in composts is of great interest, though troublesome to execute.
7th. As regards the ash, its red color indicates _iron_. Pouring hydrochloric acid upon it, causes effervescence in the presence of _carbonate of lime_. This compound, in most cases, has been formed in the burning, from humate and other organic salts of lime. _Sand_, or _clay_, being insoluble in the acid, remains, and may be readily estimated.
_Phosphoric acid_ and alkalies, especially _potash_, are, next to lime, the important ingredients of the ash. _Magnesia_ and _sulphuric acid_, rank next in value. Their estimation requires a number of tedious operations, and can scarcely be required for practical purposes, until more ready methods of a.n.a.lyses shall have been discovered.
8th. The quant.i.ty of _matters soluble in water_ has considerable interest, but is not ordinarily requisite to be ascertained.
6.--_Composition of Connecticut Peats_.
In the years 1857 and 1858, the author was charged by the Connecticut State Agricultural Society[8] with the chemical investigation of 33 samples of peat and swamp muck, sent to him in compliance with official request.
In the foregoing pages, the facts revealed by the laborious a.n.a.lyses executed on these samples, have been for the most part communicated, together with many valuable practical results derived from the experience of the gentlemen who sent in the specimens. The a.n.a.lytical data themselves appear to me to be worthy of printing again, for the information of those who may hereafter make investigations in the same direction.--See Tables I, II, and III, p.p. 89, 90, and 91.
The specimens came in all stages of dryness. Some were freshly dug and wet, others had suffered long exposure, so that they were air-dry; some that were sent in the moist state, became dry before being subjected to examination; others were prepared for a.n.a.lysis while still moist.
A sufficient quant.i.ty of each specimen was carefully pulverized, intermixed, and put into a stoppered bottle and thus preserved for experiment.
The a.n.a.lyses were begun in the winter of 1857 by my a.s.sistant, Edward H.
Twining, Esq. The samples 1 to 17 of the subjoined tables were then a.n.a.lyzed. In the following year the work was continued on the remaining specimens 18--33 by Dr. Robert A. Fisher. The method of a.n.a.lysis was the same in both cases, except in two particulars.
In the earlier a.n.a.lyses, 1 to 17 inclusive, the treatment with carbonate of soda was not carried far enough to dissolve the whole of the soluble organic acids. It was merely attempted to make _comparative_ determinations by treating all alike for the same time, and with the same quant.i.ty of alkali. I have little doubt that in some cases not more than one-half of the portion really soluble in carbonate of soda is given as such. In the later a.n.a.lyses, 18 to 33, however, the treatment was continued until complete separation of the soluble organic acids was effected.
By acting on a peat for a long time with a hot solution of carbonate of soda, there is taken up not merely a quant.i.ty of organic matter, but inorganic matters likewise enter solution. Silica, oxyd of iron and alumina are thus dissolved. In this process too, sulphate of lime is converted into carbonate of lime.
The total amount of these soluble inorganic matters has been determined with approximate accuracy in a.n.a.lyses 18 to 33.
In the a.n.a.lyses 1 to 17 the collective amount of matters soluble in water was determined. In the later a.n.a.lyses the proportions of organic and inorganic matters in the water-solution were separately estimated.
The process of a.n.a.lysis as elaborated and employed by Dr. Fisher and the author, is as follows:
I. To prepare a sample for a.n.a.lysis, half a pound, more or less, of the substance is pulverized and pa.s.sed through a wire sieve of 24 meshes to the inch. It is then thoroughly mixed and bottled.
II. 2 grammes of the above are dried (in tared watch-gla.s.ses) at the temperature of 212 degrees, until they no longer decrease in weight. The loss sustained represents the _amount of water_, (according to MARSILLY, Annales des Mines, 1857, XII., 404, peat loses carbon if dried at a temperature higher than 212 degrees.)
III. The capsule containing the residue from I. is slowly heated to incipient redness, and maintained at that temperature until the organic matter is entirely consumed. The loss gives the total amount of _organic_, the residue the total amount of _inorganic_ matter.
NOTE.--In peats containing sulphate of the protoxide of iron, the loss that occurs during ignition is partly due to the escape of sulphuric acid, which is set free by the decomposition of the above mentioned salt of iron. But the quant.i.ty is usually so small in comparison with the organic matter, that it may be disregarded. The same may be said of the combined water in the clay that is mixed with some mucks, which is only expelled at a high temperature.
IV. 3 grammes of the sample are digested for half an hour, with 200 cubic centimeters (66.6 times their weight,) of boiling water, then removed from the sand bath, and at the end of twenty-four hours, the clear liquid is decanted. This operation is twice repeated upon the residue; the three solutions are mixed, filtered, concentrated, and finally evaporated to dryness (in a tared platinum capsule,) over a water bath. The residue, which must be dried at 212 degrees, until it ceases to lose weight, gives the _total amount soluble in water_. The dried residue is then heated to low redness, and maintained at that temperature until the organic matter is burned off. The loss represents the amount of _organic matter soluble in water_, the ash gives the quant.i.ty of _soluble inorganic matter_.
V. 1 gramme is digested for two hours, at a temperature just below the boiling point, with 100 cubic centimeters of a solution containing 5 _per cent._ of crystallized carbonate of soda. It is then removed from the sand bath and allowed to settle. When the supernatant liquid has become perfectly transparent, it is carefully decanted. This operation is repeated until all the organic matter soluble in this menstruum is removed; which is accomplished as soon as the carbonate of soda solution comes off colorless. The residue, which is to be washed with boiling water until the washings no longer affect test papers, is thrown upon a tared filter, and dried at 212 degrees. It is the _total amount of organic and inorganic matter insoluble in carbonate of soda_. The loss that it suffers upon ignition, indicates the amount of _organic matter_, the ash gives the _inorganic_ matter.
NOTE.--The time required to insure perfect settling after digesting with carbonate of soda solution, varies, with different peats, from 24 hours to several days. With proper care, the results obtained are very satisfactory. Two a.n.a.lyses of No. 6, executed at different times, gave _total insoluble in carbonate of soda_--1st a.n.a.lysis 23.20 _per cent._; 2d a.n.a.lysis 23.45 _per cent._ These residues yielded respectively 14.30 and 14.15 _per cent._ of ash.
VI. The quant.i.ty of _organic matter insoluble in water but soluble in solution of carbonate of soda_, is ascertained by deducting the joint weight of the amounts soluble in water, and insoluble in carbonate of soda, from the total amount of organic matter present. The _inorganic matter insoluble in water, but soluble in carbonate of soda_, is determined by deducting the joint weight of the amounts of inorganic matter soluble in water, and insoluble in carbonate of soda, from the total inorganic matter.
VII. The amount of nitrogen is estimated by the combustion of 1 gramme with soda-lime in an iron tube, collection of the ammonia in a standard solution of sulphuric acid, and determination of the residual free acid by an equivalent solution of caustic potash and a few drops of tincture of cochineal as an indicator.
The results of the a.n.a.lyses are given in the following Tables. Table I.
gives the direct results of a.n.a.lysis. In Table II. the a.n.a.lyses are calculated on dry matter, and the nitrogen upon the organic matters.
Table III. gives a condensed statement of the external characters and agricultural value[9] of the samples in their different localities, and the names of the parties supplying them.
TABLE I.-COMPOSITION OF CONNECTICUT PEATS AND MUCKS.
KEY: A - _Soluble in water._ B - _Insol. in water, but soluble in carbonate of soda._ C - _Insol. in water and carbonate of soda._ D - _Total._ E - _Water._ F - _Nitrogen._ G - _Total matters soluble in water._
-------------------------+-----------------------+
ORGANIC MATTER.
_From Whom and
-----+-----+-----+-----+ Whence Received_
A
B
C
D
-------------------------+~~~~~v~~~~~+-----+-----+ 1. Lewis M. Norton.
Goshen Conn.
17.63
34.79
52.42
2. " " "
60.02
11.65
71.67
3. " " "
50.60
29.75
80.35
4. Messrs. Pond & Miles.
" Milford Conn.
65.15
11.95
77.10
5. " " "
67.75
16.65
84.40
6. Samuel Camp.
Plainville Conn.
43.20
8.90
52.10
7. Russell U. Peck.
Berlin Conn.
38.49
30.51
69.00
8. Rev. B. F. Northrop.
Griswold Conn.
42.30
10.15
52.45
9. J. H. Stanwood.
Colebrook Conn.
49.65
7.40
57.05
10. N. Hart, Jr.
West Cornwall Conn.
55.11
10.29
65.40
11. A. L. Loveland.
North Granby "
38.27
2.89
41.16
12. Daniel Buck, Jr.
Poquonock "
27.19
48.84
76.03
13. " " "
33.66
40.51
74.17
14. Philip Scarborough
Brooklyn Conn.
51.45
25.00
76.45
15. Adams White.
Brooklyn "
54.38
23.14
77.52
16. Paris Dyer.
Brooklyn "
18.86
5.02
23.88
17. Perrin Scarborough.
Brooklyn Conn.
43.27
16.83
60.10
18. Geo. K. Virgin.
Collinsville Conn.
2.21
20.57
8.25
31.03
19. " " "
1.12
9.19
5.10
15.41
20. " " "
0.72
9.31
3.65
13.68
21. S. Mead.
New Haven Conn.
3.30
40.52
8.20
52.02
22. Edwin Hoyt.
New Canaan "
2.84
13.42
7.55
23.81
23. " " "
2.34
13.49
8.05
23.88
24. " " "
1.15
17.29
8.00
26.44
25. A. M. Haling.
Rockville "
3.43
52.15
8.65
64.23
26. " " "
3.87
71.57
8.44
83.88
27. " " "
3.87
44.04
4.25
52.16
28. Albert Day.
Brooklyn "
2.45
46.25
6.35
55.05
29. C. Goodyear.
New Haven "
1.80
45.42
10.35
57.57
30. Rev. Wm. Clift
Stonington "
3.33
51.68
9.80
64.81
31. Henry Keeler.
South Salem N. Y.
2.13
45.12
12.05
59.30
32. John Adams.
Salisbury Conn.
1.71
42.87
10.65
55.23
33. Rev. Wm. Clift.
Stonington "
5.40
16.72
7.25
29.37
-----
Average
2.06
-------------------------+-----------------------+-----+-----+-----
INORGANIC MATTER.
_From Whom and
-----+-----+-----+-----
Whence Received_
A
B
C
D
E
F
G -------------------------+-----+-----+-----+-----+-----+-----+----- 1. Lewis M. Norton.
Goshen Conn.
35.21
12.37
1.28
1.54 2. " " "
8.00
20.33
1.85
3. " " "
4.52
15.13
1.90
2.51 4. Messrs. Pond & Miles.
" Milford Conn.
3.23
19.67
1.20
1.63 5. " " "
2.00
13.60
.95
3.42 6. Samuel Camp.
~~~~~v~~~~~
Plainville Conn.
14.90
14.80
29.20
18.70
2.10
2.50 7. Russell U. Peck.
Berlin Conn.
13.59
17.41
1.62
2.61 8. Rev. B. F. Northrop.
Griswold Conn.
34.70
12.85
1.31
1.64 9. J. H. Stanwood.
Colebrook Conn.
4.57
38.38
1.23
1.83 10. N. Hart, Jr.
West Cornwall Conn.
14.89
19.71
2.10
6.20 11. A. L. Loveland.
North Granby "
47.24
11.60
1.00
.75 12. Daniel Buck, Jr.
Poquonock "
5.92
18.05
2.40
2.94 13. " " "
8.63
17.20
2.40
1.80 14. Philip Scarborough.
Brooklyn Conn.
7.67
15.88
1.20
1.43 15. Adams White.
Brooklyn "
9.03
13.45
2.89
5.90 16. Paris Dyer.
Brooklyn "
67.77
8.35
1.03
2.63 17. Perrin Scarborough.
Brooklyn Conn.
25.78
14.12
0.86
15.13 18. Geo. K. Virgin.
Collinsville Conn.
0.32
9.41
48.05
57.78
11.19
0.64
2.53 19. " " "
0.28
1.08
48.65
50.01
34.58
0.34
1.40 20. " " "
0.25
0.76
28.20
29.21
57.11
0.28
.97 21. S. Mead.
New Haven Conn.
2.60
10.02
23.90
36.52
11.46
1.51
5.90 22. Edwin Hoyt.
New Canaan "
2.72
19.88
46.30
68.90
7.29
0.45
5.56 23. " " "
1.54
12.42
56.20
70.16
5.96
0.90
3.88 24. " " "
1.67
14.13
51.10
66.90
6.66
1.01
2.82 25. A. M. Haling.
Rockville "
0.35
0.16
4.90
5.41
30.36
1.62
3.78 26. " " "
0.23
1.98
2.21
13.91
1.32
4.10 27. " " "
0.51
4.07
5.05
9.63
38.21
1.88
4.38 28. Albert Day.
Brooklyn "
0.32
0.65
5.40
6.37
38.58
0.84
2.77 29. C. Goodyear.
New Haven "
0.35
7.98
18.80
27.13
15.30
1.68
2.15 30. Rev. Wm. Clift
Stonington "
2.82
5.86
8.68
26.51
0.95
6.15 31. Henry Keeler.
South Salem N. Y.
0.78
3.79
16.70
21.27
19.43
1.57
2.91 32. John Adams.
Salisbury Conn.
1.02
1.33
14.35
16.70
28.07
1.76
2.73 33. Rev. Wm. Clift.
Stonington "
7.40
6.40
48.05
61.85
8.78
1.32
2.80
-----
-----
----- Average
1.44
1.37
3.72
