THE COTTAGE GARDENER AND COUNTRY GENTLEMAN, Janpaky 25, 1859. 
267 
than other Peas not so treated. The seeds of Acacia lophantha 
also produced seedlings after being boiled in water for five 
minutes. The effects produced by this high temperature, are to 
permanently soften the cuticle of the seed, and render it more 
readily permeable by the air; also aiding the conversion of the 
starchy components of the seed into saccharine matter; but if 
the boiling be continued until the composition of the germen is 
altered, the germinating power of the seed, in every instance, is 
destroyed. 
These facts lead to the very important inquiry, whether the 
soil has any influence over the temperature occurring to the seed, 
and to the roots of plants placed beneath its surface ? The 
researches of M. Schubler were the first to answer this query in 
the affirmative. This distinguished German chemist found, that 
when the temperature of the upper surface of the earth was 77° 
in the shade, various soils, exposed to the sun from eleven to 
three, in vessels four inches square and hi"" 
attained the temperatures shown in this table. 
Siliceous sand, bright yellowish grey . 
Calcareous sand, whitish grey 
Gypsum, bright white grey . 
Sandy clay, yellowish 
Loamy clay, yellowish . , 
Stiff clay, or brick earth, yellowish grey . 
Fine blueish grey clay . 
Lime, white .... 
Magnesia, pure white. 
Garden mould, blackish grey 
Arable soil, grey 
Slaty marl, brownish red . 
The results of M. Schubler’s experiments demonstrate that 
which our knowledge of the laws of caloric woidd have 
induced us to pre-suppose—namely, that light-coloured earths, 
by reason of their reflecting most rays of heat, 
are warmed much more tardily than dark- 
eoloured earths. It was this conclusion which 
induced us, many years since, to try the effect of 
sprinkling coal ashes over rows of autumn- sown 
Peas. The Peas invariably appeared above the soil 
some days before those in rows not similarly 
treated. This acceleration of vegetation continued 
equally marked throughout then’ growth, and is 
further explained by other experiments of M. 
Schubler, which testify that those soils in the 
above table which absorbed the heat most readily 
retained it most tenaciously, and, consequently, 
were longest cooling. Magnesia cooled in one 
hour and twenty minutes as much as the garden 
mould did in two hours and sixteen minutes, and the slaty marl 
in three hours and twenty-six minutes. 
From more recent experiments, made in the Horticultural 
Society’s Garden at Chiswick, and in other parts of England, we 
have the following results, confirming M. Schubler’s experiments. 
In the Chiswick garden,— 
Dec. 
January of 1845, as well as the temperature of the soil at six 
inches, and at twelve inches below its surface. The soil is black, 
rich, and siliceous, resting on a chalky subsoil:— 
If an inch 
deep, 
Wet. 
Dry. 
. 99.1 
121.6 
. 99.3 
112.1 
. 97.3 
110.5 
. 98.2 
111.4 
. 99.1 
112.1 
. 99.3 
112.3 
. 99.5 
113.0 
. 96.1 
109.4 
. 95.2 
108.6 
. 99.5 
113.5 
. 97.7 
111.7 
. 101.8 
115.3 
January. 
Night. 
Day. 
Gro 
6 in. 
und. 
12 in. 
r 
January. 
1 
35 
44 
39 
so 
1 
2 
34 
38 
374 
39 
2 
3 
25 
40 ' 
34 
37 
3 
4 
32 
47 
35 
36 
4 
5 
38 
51 
38 
38J 
5 
6 
42 
52 
41 
40 
6 
7 
45 
50 
42* 
414 
7 
8 
35 
42 
40 
41 
8 
9 
32 
39 
27 i 
40 
9 
10 
35 
39 
374 
394 
10 
11 
43 
50 
42 
4l| 
11 
12 
39 
45 
42 
42 
12 
13 
38 
45 
41 
414 
13 
14 
36 A 
49 
40 
■D4 
14 
13 
38 
46 
40 
41 
15 
16 
38 
46 
40 
41 
16 
17 
39 
45 
40 
41 
17 
18 
38 
48 
40 
41 
18 
19 
32 
46 
38 
40 A 
19 
20 
34 
45 
38 
40 
20 
21 
30 
42 
36 
89 
21 
22 
25 
47 
35 
39 
22 
23 
35 
49 
40 
394 
23 
24 
36 
49 
40 
404 
24 
25 
29 
51 
37 
39 
25 
26 
42 
47 
41 
41 
26 
27 
34 
46 
38 
39 
27 
28 
28i 
40 
35 
37 A 
28 
29 
27 
39 
34 
37 
29 
30 
31 
39 
38 
37 
so 
31 
25 
35 
S3 
36 
31 
Professor Dove, of Berlin, published, in 1855, the following 
table, giving the mean results of his observations made at that 
city during the five previous years :— 
4 feet 
On the 
At a depth below the surface of 
Differ- 
the 
ground. 
of the 
ground. 
1 foot. 
14 ft. 
2 feet. 
24 ft. 
3 feet. 
4 feet. 
k feet. 
ence. 
January. 
32.67 
33.35 
36.72 
37.80 
38.18 
39.02 
40.07 
42.44 
44.44 
11.09 
February . 
32.74 
32.60 
36.18 
37.19 
37.67 
38.23 
39.31 
41.47 
43.13 
10.53 
March . 
35.53 
36.05 
37.33 
38.00 
38.14 
38.54 
39.17 
40.91 
42.28 
6.23 
April . 
45.68 
44.80 
43.72 
43.83 
43.52 
43.63 
43.43 
43.88 
44.01 
0.7(j 
May . 
58.59 
57.24 
52.13 
51.48 
50.7G 
50.72 
49.57 
48.96 
48.15 
9.09 
June . 
63.61 
60.48 
57.80 
58.15 
56.68 
56.66 
55.26 
54.41 
52.99 
7.49 
July . 
68.47 
65.43 
62.46 
01.04 
60.55 
60.48 
59.00 
57.78 
56.21 
9.22 
August . 
64.91 
61.97 
60.57 
60.53 
60.50 
60.66 
59.72 
59.00 
57.85 
4.12 
September ... 
58.16 
56.72 
57.35 
57.78 
58.10 
58.41 
58.01 
58.01 
57.49 
0.77 
October . 
49.43 
48.31 
51.12 
51.80 
52.25 
52.52 
52.97 
54.18 
54.88 
6.57 
November ... 
38.63 
38.79 
43.94 
45.07 
45.68 
46.44 
47.43 
49.55 
51.26 
12.47 
December. 
34.43 
34.97 
39.20 
40.19 
40.68 
41.69 
42.59 
45.00 
47.09 
12.12 
1844. 
Minimum 
Earth 
Earth 
Temp, of air. 
1 foot deep. 
2 feet dec 
4 
. 22 
40 
43 
5 
14 
38 
43 
6 
. 14 
37 
42 
7 
. 20 
37 
41 
8 
36 
41 
9 
. 28 
36 
40 
10 
. 28 
40 
11 
. 22 
36 
39 
In a stiffish loam on a gravelly subsoil near Sheffield, after a 
fortnight’s exposure to a minimum temperature, varying between 
21° and 31°, the soil had frozen to a depth of four inches and a 
half. But at lower depths the temperatures were as follows :— 
At 6 inches .... 34° 
„ 12 „.36F 
„ 24 „ .... 39° 
In every instance the lighter soils were frozen to a less depth 
than the more tenacious, the former in no case having the frost 
penetrate lower than six inches, but in heavy soils two inches 
deeper.—( Gardeners' Chronicle.) 
The following table, kept by Mr. Sharp, the scientific manager 
of the Winchester gas-works, shows the lowest temperature of 
the air at night, and its highest temperature by day, during the 
The temperature of the soil, especially near the surface, varies 
considerably, according to the mildness or coldness of the season. 
Dr. Lindley very erroneously concluded from this fact, that 
flower-seeds shovdd not be committed to the ground until it 
attained a temperature of 46°. So far from this precaution being 
needful, it is a well-known fact, as already stated, that seeds—are 
uninjured by the severest frosts, unless these occur after the seeds 
have germinated. In confirmation of this, one of our best 
gardeners, Mr. R. Fish, writes as follows :— 
“ Natural-sown seeds come up earlier, and, what is strange, 
will often, at first, look more healthy than plants from seed sown 
carefully by the hand. This is owing to the fact, that the seeds 
scattered from the plant—at least, those of them that grow, are 
almost certain to be little covored. When we sow seeds early, 
and cover them as carefully as we can, yet this covering, if the 
ground is at all loamy, is apt to enclose the seeds in an air-tight 
covering after heavy rains, and thus germination is impossible. 
Hence the importance of sowing all seeds in the open air when 
the ground is dry. The seeds, from the moisture even then in 
the earth, and the free admission of air, begin to swell at once. 
If coated with loamy, moist soil, air is excluded, and the seeds 
either rot, or refuse to vegetate. Seeds thrown from the seed- 
vessel on the surface of the ground, may, in many cases, be 
scorched up by the sun ; but, in many cases, also, they may just 
be sufficiently sheltered by the crumblings and the interstices of 
small lumps of soil, as to be in the best position for germinating, 
whenever the heat is sufficient for that purpose. Few things feel 
the first effects of frost more than the tender Purslanes, such as 
Portulaca splendens, Thellusonii, grandifiora , and their varieties ; 
and yet the self-sown seeds pass the winter apparently uninjured.” 
— (Cottage Gardener.) 
