November 30, 1882. ] JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 497 
there are two specimens about 25 or 30 feet high, and in admirable 
condition.” In 1872 a similar statement appeared in another 
paper, but the credit of being the purchaser was given to the 
Duke of Devonshire, and the price two hundred guineas. It is 
curious upon what ground such statements can have originated. 
Neither is correct. The truth is this : Mr. Bidwill, on visiting 
England in 1843, brought with him a small plant about a foot in 
height, growing in a flower pot. He put it in the hands of Mr. 
Stevens, the auctioneer, for sale, the upset price being £25 ; but 
no bidder was found for it, and I being present Mr. Bidwill asked 
me to take it to Kew and take charge of it for him. I brought it 
home in my hand. Such is the history of the fine Araucaria Bid- 
willi now in the conservatory at Kew. It was some time before 
other plants were introduced which came to Kew, and l have no 
recollection of hearing that either the Duke of Devonshire or the 
Duke of Northumberland becoming possessed of plants at that 
time ; indeed, I am not aware of any large plants being in the 
country than those at Kew.— J. Smith, Ex-Curator of the Royal 
Gardens, Kew. 
EARLY POTATOES. 
The weather here during the last three weeks has been most 
unfavourable for any outdoor work. We have had three weeks’ 
storm and almost constant rain followed by frost on the last three 
nights of 2°, 3°, and 5° Fahr. below the freezing point. I fortu¬ 
nately had the last of my field Potatoes secured a short time 
previously, but I am satisfied one-third of that crop is still undug 
in Ireland, and a large fraction of that is hopelessly injured. I 
examined some left behind on the surface in the vegetable grounds 
and others that were an inch beneath the surface. They were all 
soft, spongy, and wholly unfit for anything but manure. After 
saving several acres of both Champions and Magnum Bonums I 
have had not one stone of diseased tubers, though of less size than 
last year, from early blighting. It is not uncommon, especially 
in suburban gardens where space is limited, to grow Potatoes in 
the same place year after year, but it is undesirable. If the 
Potato must be grown and the same land must be used lime 
would be desirable as a corrective of the sourness frequently 
noticed. I attribute the above satisfactory results to the crop 
being grown in new land and to the seed being obtained from 
a different district. 
This brings me to the principal point I intended to say a few 
words about—Autumn versas Spring-planted Potatoes. Two years 
since I planted four lines each of Yeitch’s Ashleaf Kidney. Snow¬ 
flake, Early Rose, Beauty of Hebron, Bresee’s Peerless, and Gram¬ 
pian the 20th of October 6 inches deep, using stable manure. 
The winter came unusually severe, and I put on a few inches 
more of litter later on. A large number decayed, especially of the 
Kidneys and Snowflake ; and though I removed a quantity of the 
surface of the drills in April to permit the heat from the sun’s 
rays more play, the vast majority were later than those planted 
early in March, and with puny growths that never became robust. 
I make these few remarks, as I see one of your correspondents has 
inquired on the subject. I shall not try the experiment again. 
I am now trying several varieties of Cauliflower exposed in the 
seed bed for the winter, and shall tell you the result later on. 
With frame culture the trouble, and subsequent dissatisfaction 
“ buttoning,” See., has induced me to try a hardier system of 
treatment.—W. J. M., Clonmel. 
OF HUMUS. 
(Continued from page 473 .) 
“ Humus,” says Ville, “has its origin in the actual substances 
of plants, which, by a kind of spontaneous decomposition, has 
lost a certain quantity of hydrogen and oxygen in the form of 
water,” and he tells us that many intelligent men place humus 
in the foremost rank as a fertilising agent; but, as he adds, let 
us “ go to the root of the matter, gaining our light and informa¬ 
tion from experience. How and under what circumstances does 
humus act favourably ?” As mentioned in the latter part of my 
former letter, the views of Liebig upon this important ingredient 
of soils appear to have been somewhat misunderstood or imper¬ 
fectly stated. I think it, therefore, the more necessary in what I 
have to say to let him speak for himself. 
“Up to a few years ago,” Liebig writes in his “Letters on 
Modern Agriculture,” “ scientific agriculture taught, and all prac¬ 
tical men firmly believed, that the productiveness of a soil was 
dependant on the quantity of humus, or carbonaceous remains of 
a preceding vegetation, contained in it. Without raising doubts 
on the efficacy in certain cases of the organic matter of farmyard 
manure, ii may be asserted that nobody who possesses any know¬ 
ledge of the matter now believes that the produce of a field in 
carbonaceous substances bears any proportion to the amount of 
humus in the soil, and that its fertility can in reality be estimated, 
as was formerly supposed, by this humus.” Inasmuch as before 
Liebig wrote, “ Humus had the honour,” as Ville says, “ of serving 
as an explanation for everything that could not be understood,” 
the terms of this expression of opinion cannot, I think, be cavilled 
at. Liebig showed incontestably that it was utterly impossible 
that all the carbon found in plants could be derived from the 
amount of humus in the soil; and therefore, whether humus is 
capable of supplying nourishment directly to vegetation or not, 
we may leave this part of the question for the present, and con¬ 
sider how and when humus certainly exerts a beneficial action. 
We shall find, I believe, that we may safely credit it with more 
good effects than would be supposed from the above quotation from 
Liebig, and certainly with effects sufficiently important to justify 
my inquiry. 
“ The first of its good effects,” Ville says, “ is that, like clay, it 
possesses the property of absorbing a great deal of water, thus 
contributing to the maintenance of the humidity of the soil. If, 
however, we remember that the soil contains only a very small 
per-centage of humus, it is very difficult to allow that such small 
quantities have the power of modifying the physical condition of 
the soil.” The remainder of this letter will be occupied by the 
inquiry whether, notwithstanding the apparent difficulty in be¬ 
lieving in the modifying powers of comparatively small quantities 
of humus, there may not be more difficulty in rejecting the 
evidence in favour of their important influence. 
The fact is, as it appears to me, Ville’s experiments on another 
prominent function of humus, to which I shall allude hereafter, 
led him to underrate the effects produced by the humidity which 
itenc.-urages—effects which will not be despised by those who, 
like your readers, have continually before their eyes the bene¬ 
ficial influence of “mulching.” Davy may perhaps be looked 
upon in the present day as somewhat antiquated, but his results, 
deduced from actual experiment, must still be regarded with the 
utmost respect. He made careful investigations ou the absorption 
of different soils, and he states, “ 1 have always found it greatest 
in the most fertile soils, so that it affords one method of judging 
of the productiveness of land.” Hs found that a thousand parts 
of the soils named below, after having been dried at 212°, absorbed, 
during one hour of exposure to the air, the quantities of moisture 
given in the following table. 
Sterile soil of Bagsliot Heath. 3 
Coarse sand. 8 
Fine ditto. H 
Soil from Mersea in Essex . 13 
Very fertile alluvium, Somersetshire. 16 
Extremely fertile soil of Ormiston, East Lothian. 18 
— {Davy, Ayr. Chon., 5 cd.,p. 176.) 
In the next table I give some of the results of a series of 
experiments, carried out by Schiibler, for the purpose of deter¬ 
mining the absorptive power for vapour of water of different 
kinds of earths and soils. 
The column of figures gives in thousandths the quantity of 
hygroscopic moisture absorbed, by previously dried soil from air 
contained over water (and hence nearly saturated with moisture), 
in twenty-four hours. 
Quartz sand, coarse . 0 
Lime sand. 3 
Ploughed land. 23 
Clay soil (60 per cent, of clay) ,. 28 
Fine carbonate of lime. 35 
Loam. 35 
Heavy clay soil (80 per cent, of clay) . 41 
Pure clay . 49 
Garden mould (7 per cent, of humus). 62 
Humus . 120 
From the facts expressed in the above two tables it is manifest 
that soils (though undoubtedly much depends on the fineness of 
division of their particles) may have their absorbent properties 
very largely increased by an admixture of 20 per cent, of clay, 
and that humus, the absorbent property of which is nearly 
2^ times as great as that of clay, must influence a soil to a still 
greater extent. We knowq in fact, that sandy soils which have 
little attractive force for atmospheric vapour, and are therefore 
arid and dry, may be greatly ameliorated, in this respect by ad¬ 
mixture with clay, or, which is better still, by admixture with 
humus, as is done by dressing with vegetable composts and by 
green manuring. 
At the same time, as many sterile soils contain humus in abun¬ 
dance, whilst sometimes fertile ones contain but a small propor¬ 
tion of it, it seems that humus is by no means indispensable to the 
life and full development of plants, its presence cannot be re¬ 
garded as any sure test of fertility. Yet, though this is the case, 
may we not safely regard it as a more valuable constituent, inde¬ 
pendently of the mineral salts it may contain, than Ville and 
