88 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ August 2, 1883. 
lias been applied to Onions, Lettuces, and Kidney Beans 
without injury to the plants, but resulting in the death of all 
insects with which it came in contact. On page 332 of our 
issue of April 28th, 1881, Mr. Witherspoon enforces the value 
o'f hellebore as an insecticide, and suggests that it be tried 
on phylloxera-infested Vines, firmly believing it would prove 
effectual, as he observes that “ in soil saturated with helle¬ 
bore no insect can live, and yet plants are not injured.” 
The method of using it is to dissolve 2 ozs. of the powder in 
a gallon of water, but first mixing a small portion in a 
little hot water to the consistency of cream, then adding the 
quantity of cold water required. This is worth trying, as 
also doubtless will be several other preparations that will 
suggest themselves to those specially interested in the matter. 
There is little doubt that while many persons whose 
Vines do not flourish are needlessly alarmed by the supposed 
presence of the phylloxera, there are yet other Vines seriously 
attacked with this destructive pest, of the existence of which 
the owners are ignorant. Gardeners and amateurs should 
as far as possible make themselves acquainted with the 
appearance of the root and leaves when attacked, and this 
they may do by referring to the illustrations on page 167, 
vol. i., of this Journal, the issue of August 19th, 1880. The 
attacked specimens were taken from the vineries at Norris 
Green; and on page 413, vol. ii., the issue of May 19th, 1881, 
Mr. Bardney detailed the method he adopted in clearing the 
borders from this terrible scourge of the Vine. By an 
attentive perusal of the articles referred to we think few 
persons will fail to determine whether their Vines are attacked 
with the phylloxera or not. One thing is certain—namely, 
that it is too plentiful in this country, and quite recently Vine 
roots from three districts have been sent to us seriously 
attacked with this destructive insect.] 
TOMATO CULTURE. 
I have of late observe I many inquiries in the pages of the 
Journal of Horticulture cn the subject of Tomato culture, and as 
I think my experience in the matter may be of some service to 
many who grow that most valuable fruit, I am tempted to place 
it at your disposal, and more especially because I have proved 
in years gone by that what applies to the Tomato applies exactly 
in the same way to the far more important Potato. 
I this year planted a row of Tomatoes in the centre of a newly 
planted vinery 180 feet long. One half were planted in loam 
and horse droppings prepared for a Mushroom bed, the other 
half in the same pure maiden loam, with no nitrogenous manure 
of any kind. I used a manure rich in phosphates and potash. 
The former grew far more rapidly than the latter, but when 
both came to fruit the latter produced the most splendid crop 
of the finest fruit I ever saw—some 1 lb. in weight; one was 
21 ozs. The former produced much inferior fruit both in size 
and quality, and all are attacked by the Peronospora infestans, 
while not one of those that received the phosphates and potash 
have been attacked. I send you samples of both, and I think 
you will agree with me that the case is proved against farm¬ 
yard manure as a manure for Tomatoes. 
I in the same manner and as conclusively proved last year 
that exactly the same results followed a similar experiment 
with Potatoes. No farmyard manure should ever be used for 
growing any of the Solanaceae. I might add much more, but 
have said enough to lead others to make similar experiments, 
which I am certain, if fairly carried out, will confirm mine.— 
W . Thomson, Clovenfords. 
[The large fruits are grand, large, smooth, and spotless; the 
small fruits are miserable and blotched with disease ; the quality 
of the former, too, is far superior to the latter. The result of 
the two methods of culture is very striking, and the experience 
recorded valuable.] 
GARDEN CHEMISTRY. 
( Continued from page 68.) 
THE SOURCES AND USE OF NITROGEN. 
While plants must have nitrogen in the soil or fail to thrive, it 
eon l ains no store naturally, nor yet will it retain one long, though 
a tiicially supp’ied. True, all fertile soils contain it in the form of 
a tr ites, ammon'a, or in the remains of organic matter ; but there can 
be little doubt that this has all originally been derived from the 
atmosphere. Every lightning flash produces some hydric nitrate ; 
and though in our country the amount thus produced is not great, in 
tropical countries, where thunderstorms are not only much more 
frequent but much more violent., considerable quantities are thus 
formed and washed into the earth by the descending rain. Ammonia, 
again, is largely present in the gases discharged from volcanoes ; and 
though the annual amount thus thrown into the atmosphere is not 
great, the quantity after long centuries, and even thousands of years 
of accumulation in the soil, will form no inconsiderable supply ; for, 
though under our methods of cultivation nitrogen is lost from our 
fields and gardens, vegetation under natural conditions prevents this 
loss. 
The amount of nitrogen which the soil gains from the air under 
ordinary circumstances is by no means inconsiderable. At Rotham- 
stead, according to the authorities there, the soil gains nearly 7 lbs. of 
combined nitrogen from the air, being washed thence by rain. This 
is chiefly in the form of ammonia, but about a ninth is in the form of 
nitric acid. In some districts more is thus gained by the soil, and in 
others less. In “ Air and Rain,” by Angus Smith, it is stated that in 
the rain water at Glasgow there are 9T parts of ammonia and 2-436 
of nitric acid in 1,000,000 parts of water. In the rain water of 
Manchester the proportions are considerably less, and in London very 
much so. At Valencia, on the coast of Kerry, where the air is very 
pure, it is very small. The following table will serve to illustrate 
the varying amounts. Taking Valencia (county Kerry) as a standard 
and representing one part, the other figures will show how much 
nitrogen exists in the air in the vicinity of towns, and especially 
manufacturing ones :— 
Ammonia. 
Nitric acid. 
Valencia (Ireland) 
... 1-00 
1-00 
Inland parts of England 
... 5-94 
2-02 
Sea-coast places in Scotland 
.. 110 
1-01 
London . 
... 19-17 
2-27 
Manchester 
... 35-94 
2-79 
Glasgow. 
... 50-55 
672 
On the Continent it has been estimated that the soil at Kuschen 
(Posen) benefi s to the amount of nearly 2 lbs. per acre, but at 
Proskau (Silesia) the gain is calculated to be over 20 lbs. 
Nitrogen exists to a greater or lesser extent in what -we have 
named “ garden manures,” but it is only in manures that contain much 
pure dropping 1 :, and which have been carefully made and protected, 
that it exists to any extent worth mentioning. Even good leaf soil 
seldom contains a quarter per cent, of nitrogen, and an ordinary 
sample of farmyard manure gives something like a half per cent. 
When properly made and cared for, manure containing even more 
than the usual quantity of straw will often contain 1^ per cent., or 
even more, and is, of course, three times the value of that only 
containing half per cent. Stableyard manure from stables where 
horses are “ hard fed,” and where abundance of straw is used, when 
thrown together in a heap heats with extreme violence, and this 
causes “firing,” or “ fire-fanging ” as it is called in different parts of 
the country. This excessive heat drives off the ammonia as fast as it 
forms into the air, and the residue is of very little value. That which 
gave it its value is gone ; “its spirit has fled.” When, on the other 
hand, the heap is made thoroughly moist, but not w T et, with urine 
preferably, and occasionally turned to prevent it heating too much, 
the ammonia formed is absorbed by the mass, and in time becomes 
converted into nitric acid. Even when this is done it is frequently 
lost. During the fermentation organic acids (humic, ulmic, carbonic, 
&c.) are formed and combine with the ammonia. The resulting salts 
are very soluble and are easily washed away. Indeed, there are few 
even well-cared-for manure heaps from which a rich brown liquid 
may not be seen draining away. This liquid is largely impregnated 
with the valuable nitrogen in different forms. Heaps of manure 
spread thinly, especially in wet districts, frequently have all that is 
worth retaining washed out of them by rain. Careful building will 
reduce this waste to a minimum, but thatching, covering with soil 
placed ridge fashion, or, placing under cover, is better still. Manure 
so managed is at least worth double that which is first “ fired ” and 
then “washed.” 
Urine is especially rich in nitrogen. Of course the bulk of urine 
is water, but when pure a ton of it is worth from two to three times 
as much as an equal amount of ordinary manure, even though it is 
deficient in phosphoric anhydride. The nitrogen in urine is present 
in the form of urea, which is a substance as valuable as ammonia. It 
is soluble in water, cannot be precipitated by ordinary means, and can 
be utilised at once by plants instead of requiring to be converted into 
nitric acid, as ammonia has, although it also assumes that form. It 
is a very different substance from ammonia, but is readily converted 
into it by fermentation. Its composition will be easily understood 
from the following arrangements of their constituent elements. 
Ammonia has this formula— NH3 ; urea CH4 N3 O. To those not 
