September 6.1894. 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
21,3 
T he loss o£ chlorophyll in plants is generally attributed by 
scientists to a deficiency of iron in the soil, but the facts are 
few soils are defective in that respect, and the form in which 
it is generally advised to be employed—namely, the sulphate, is a 
clear indication that the sulphur is the exciting cause of the 
activity of the chlorophyll granules, and not the iron. Of course, 
in the sulphate form the iron is available, but it is certain that 
without the sulphur iron has practically no effect on the increased 
or otherwise manufacture of the essential pigment—chlorophyll. 
Indeed, iron alone has the result of turning Hydrangeas blue, even 
giving a violet tint to pink, rose, and red Roses—that is, it 
heightens their colour and in anything but green. The green Rose 
does not put on a deep shade when treated with iron oxide, but 
assumes a lilac tint, though it behaves differently when supplied 
with sulphate of iron, becoming hardier in plant and the flowers 
decisively larger and yellowish green in colour. Thus xanthophyll 
is promoted by the iron as well as chlorophyll by the sulphur in 
the leaves. Sulphur, as a separate application, will not do anything 
of this kind, in fact it is as bad or worse in the soil as an excess 
of iron, therefore we must have recourse to the sulphate, which in 
any form—the base having manorial or essential soil constituent 
value—increases the growth of crops, according to Professor 
A. Muntz, 13 54 per cent. An increase of 30 2 per cent, is claimed 
for applications of iron sulphate, but the increase of chlorophyll or 
leaf-green is not more than 9 6 per cent, where there is an ascer¬ 
tained deficiency of available iron in the soil. 
The component elements of a sulphate are the base—potash, 
magnesia, soda, lime, iron, sulphur, and oxygen, and the point to be 
determined is, of what the active manorial ingredient in these 
respective compounds consists. Oxygen may do something, but it 
does very little in oxide of iron ; in fact, both are so locked up 
that only a supply of ammonia can separate them to beneficial 
influence on crops. 
Lime is a great liberator of nitrogenous matter ; in fact, it 
seems to have consumed it all in the case Mr. Molyneux (page 170) 
refers to. With the sulphur added, or as gypsum, it causes a great 
increase of chlorophyll, even in leguminous plants, which abstract 
free nitrogen from the atmosphere, therefore the active principle 
lies in the sulphur, not in the lime. 
In soda sulphate (Glauber salt) there is more than half water, 
though crystals rapidly lose their water when exposed to the air, 
and yield the anhydrous salt as a white powder. The effect of its 
application is to produce a sturdier plant, there being no perceptible 
increase of chlorophyll, but of xanthophyll, the yellow colouring 
matter of leaves, flowers, and fruits, and the soda certainly nullifies 
the nitrogen, hence the value of salt or soda as hardening the 
tissues of plants, especially the epidermal, as they place such sub¬ 
stances as soda, silica, iron, magnesia, and lime mainly as accumula¬ 
tions on the aged cell walls—those of the bark and wood. Any 
good, therefore, obtained from sulphate of soda is due to the 
sulphur and the antiseptic properties of the soda. 
Sulphate of magnesia has a marked effect on the production of 
chlorophyll in leguminous plants. Indeed, it is needful to the 
formation of chlorophyll granules, which are admittedly the seat 
of those operations that first construct organic substance from 
inorganic. The sulphur may energise the protoplasm—no more, 
No. 741.—VoL. XXIX., Third Series 
yet the magnesia is utilised, worked up into chlorophyll granules, 
which is proved by magnesia being a constant ingredient of 
chlorophyllan, a crystallised derivative of chlorophyll. Magnesia 
and lime are believed to be concerned in the transport of protein 
bodies, as they occur in the aleurone (organised albuminoid 
granules) of seeds, and investigations in this direction may possibly 
lead to discoveries as regards shanking in Grapes and canker (not 
caused by fungi) in Apple trees. 
Potash sulphate—the “high-grade” used for manorial pur¬ 
poses—contains only 28 to 35 per cent, of potash. Consequently 
there is abundance of sulphur (or other substances), and the effect 
of its application is decisively invigorating to all plants that make 
much growth, as Beans, Peas, Clover, and Potatoes; and is an 
essential of all plants grown for their sugar—Sugar Beets, Sugar¬ 
cane, and Grapes. M. Ville was the first to demonstrate that 
without potash Vines could neither grow nor produce Grapes, and 
it is a notable fact that his formula contains the essential sulphate,, 
not in the manufactured, but in the natural state. The formula— 
Calcic superphosphate (dissolved bones), 528 lbs.; potassic nitrate 
(saltpetre), 440 lbs.; calcic sulphate (gypsum), 352 lbs., mixed, 
per acre, or 8:^ lbs. per rod, or about 5 ozs. per square yard, is 
admirable for soils deficient in lime, and I may say sulphur. This 
is the great point—M. Ville knew its value, hence the gypsum, and 
it is a natural, not a sulphate formed by an acid, such as carbonate 
of potash dissolved in diluted sulphuric acid. This sulphate is 
just the thing to take chlorophyll out of leaves, and the same may 
be said of all acid sulphates. Natural sulphates supply sulphur as 
well as the base, and when that is present in any soil enough 
sulphuric acid will be produced without need of more—indeed, 
it may add expediency to manures, but there is danger of an 
excess. 
In the case cited by Mr. Molyneux there would be at least 
18 per cent, of sulphate of lime present in the chalk soil, while the 
phosphoric acid in such usually shows a higher percentage (0 15) 
than a Kent Hop soil (010). I have held, and still do, that 
phosphoric acid is the main factor in the direction of chlorophyll 
formation along with sulphur in certain cases, which to some 
extent compensates for deficiencies of phosphoric acid. This is 
verified by soils low in the latter often containing 0 34 per cent, 
of sulphate of lime, and the growth is free through the energising' 
action of the sulphur on the protoplasm, which really causes a 
higher utilisation of the phosphoric acid than where this substance 
is more abundant but the sulphur less. 
Potash also in the chalk would be less than in an ordinary 
loamy soil, which is about 0'30 per cent., but mo’’e of that fs- 
utilised by plants than in a clay soil containing 0-76 per cent., and 
the reason is the loam contains more sulphur and not acid, like 
the 0 10 per cent, of the clay. This leads up to Mr, Molyneux’s 
experience with bones for Chrysanthemums, The application oT 
bonemeal caused the leaves to assume a pale hue, that is, the 
phosphoric acid and the nitrogen come too slowly ; when dissolved 
bone is used the phosphoric acid and the nitrogen are at once taken 
up by the plants. Possibly the sulphuric acid may so act on the 
lime of the bones as to give something analogous to and having 
the properties of a sulphate, or so act on the carbonate of lime 
forming the substratum as to form sulphate of lime, for I suppose 
it is soil from the same formation that is used for the Chrysanthe¬ 
mums as that used for the Vines. 
The question is. What prompted the change ? the sulphatic, 
phosphatic, or the nitrogenic. I have placed them in the order 
in which they stand for influence on the protoplasm, which in 
itself is a nitrogenous carbon compound consisting of five elements, 
which chemists inform us has an average composition of 52 55 per 
cent, carbon, 21'23 oxygen, 15 17 nitrogen, 6 7 hydrogen, 1 2 sulphur. 
Mechanically the cultivator can aid the supply of oxygen and it 
and hydrogen by moisture provision, carbon being derived from the 
atmosphere and is accelerated in appropriation by cleanly culture 
No. 2397.— VOE, XCL, Old Series. 
