22 JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. c January 13 , mm. 
I have examined the subject as closely, fully, and fairly as 
I have been able, with the sole object of eliciting the truth. 
Two years ago I was a disbeliever in the injurious effects of 
galvanised wire, now I am fully satisfied that it is, when new, 
highly dangerous in certain situations. It is, perhaps, too much 
to expect that all will agree with the conclusions arrived at; 
but those who differ will, of course, submit proof that the 
injury in question, that in many places has been so serious, 
has not resulted either from the escape of acid from the wire 
or the action of acid on its zinc surface from a vitiated 
atmosphere. 
Several letters relative to the injuriousness of galvanised 
wire have been received that it was not necessary to publish, 
as the writers simply repeated in substance what had pre¬ 
viously appeared in the Journal of Horticulture , but extracts 
from a few of those letters may be given. “ Civis " writes 
frcm Derby as follows :— 
“Last spring I wrote two or three letters in your Journal calling 
attention to the injurious effect of galvanised wire for tying Peach 
trees, which called forth several replies disagreeing with my opinion 
as to the injurious effect upon the trees, notwithstanding 1 had all 
the galvanised wire removed and sitbstituted copper wire instead ; 
and no one need wish to see a better lot of trees in any house. They 
are full of flower buds and the wood ripened. I enclose you a small 
branch I cut off one of the trees that is tied to the back wall of my 
Peach house, and you will see for yourself the injurious condition of 
the wood. I found this branch had rested against a galvanised peg 
stuck in the walkthrough which the copper wire ran. Yau will 
see it has eaten nearly through the branch, which in itself is a proof 
of damage the zinc wire will cause.” 
The injury to the shoot was very pronounced, and precisely 
the same effects are produced by placing a shoot in contact 
with sulphate of zinc, which corrosive substance forms on 
galvanised and not on copper wire. “ W. E.” writes from 
near Birmingham :— 
“ I planted Habrothamnus fascicularis in the border of a conserva¬ 
tory and trained it to galvanised wire. About a month after planting 
the leaves turned black and fell off, also the ends of the shoots were 
injured. I took it out of the border from the wire and potted it. 
When it had made shoots 2 or 3 inches long I returned it to the 
border. In a short time the same thing happened to it again. I 
again took it up and kept it in a greenhouse through the winter. 
The following spring I again planted it in the aforesaid border, but 
with the same results as before. T then had the wires painted, and 
the tree grew away amazingly. From observation I find that wire 
that has been in use some years to be harmless by being coated over 
with dirt, &c., which destroyed its injurious properties, and also think 
that the process of galvanising has something to do with it, some new 
wire being harmless and others very destructive.” 
Both the theories advanced receive confirmation from this 
letter. The coating of dirt, &c. (oxidation) preventing the 
sulphurous acid of the atmosphere of a smoky district acting on 
the zinc and producing the poisonous sulphate ; while some 
“ new wire being harmless and others very destructive,” 
suggests that there is “ something in ” the mechanic’s assertion 
that some wire contains more acid than others by a longer im¬ 
mersion in the bath, and that the acid afterwards “ sweats 
out ” and corrodes the plants. This view also applies to the 
following case. Mr. Allis writes from a presumably salubrious 
district, Bedfordshire :— 
“ Last spring I planted two houses with Peaches and Nectarines. 
The summer’s growth was trained to new galvanised wire ; the con¬ 
sequence is that many of the shoots are badly gummed. I have 
looked carefully through both houses, but I have not been able to 
detect a single instance of gumming except where the shoots came 
in contact with the wires. I have just had the wire painted with one 
coat of good white lead mixed with linseed oil. I am of opinion that 
one coat of paint is ample at one time, for this reason : If more than 
one coat is put on I am afraid it would scale off. Besides, it would be 
better to give the wires one good coat annually rather than two or 
three coats at one time, for at least two or three years. I have found 
that Cucumbers, Melons, and Tomatoes have been diseased where 
trained to galvanised wire. I have had my suspicions that Vines have 
been injured where the tender shoots have come in contact with the 
wire, but a3 a preventive I shall have all the wires painted with one 
coat of good white lead, and the walls with Carson’s anti-corrosion 
paint, which answers the purpose admirably. We have tried it on 
galvanised wire, but it does not adhere to it.” 
This letter repeats a remedy that, so far as I know, has 
never failed ; and it does not appear to be necessary to incur 
the expense of substituting copper for galvanised wire. 
Mr. Geddes, writing from near Derby, attributes the injury 
to the overheating of the galvanised wire by the sun. He 
states that 
“The wires in a Peach house became so hot that no young shoot 
in contact with them could escape injury. I immediately had the 
wires painted with two coats of white paint, and a gentleman sug¬ 
gested that blue paint would be equally effectual. We painted again 
with blue, and never had a shoot injured since. Last summer we had 
two Peach houses painted. The painters painted the stout iron rods 
black, and every shoot that crossed those rods was burned ; and by 
way of experiment a part was shaded from the sun and no injury 
followed there. Galvanised wire becomes too hot when not painted, 
and that is the sole cause of injury. Black or brown paint will not 
prevent the wire being heated ; white will, as it is a non-conductor 
of heat.” 
That, as the Yankees say, is a “ new notion but the over¬ 
heating theory fails to answer the question that the wire under 
notice is injurious in some cases and not in others. The sun’s 
heat is general, and is certainly as intense in the country as 
near towns—at Longleat, for instance, where galvanised wire 
is innocuous to vegetation, as near Sheffield and Derby, where 
its use is dangerous. Further, charcoal-drawn wire is black 
and safe ; and old oxidised wire is much darker than new 
galvanised wire, while the latter, and lighter-coloured, is 
unquestionably the more injurious. 
A Berkshire correspondent, “ A. L. N.,” writes as follows 
on imperfections in galvanising— 
“ Assuming for the moment that perforations in the zinc coating do 
exist—though they may, perhaps, be too minute to be visible with 
the naked eye—what will be their effect ? At each one of them we 
have two out of the three requisites for forming a galvanic cell. We 
have the two dissimilar metals iron and zinc (the latter the most 
active ordinary metal that could be found for the purpose), and at 
some near point they are perfectly connected. The only thing, there¬ 
fore, that is required for producing a slight local electric current is a 
drop of water, whilst a drop containing an acid will give a consider¬ 
ably stronger current. Drops of either kind may be supplied by the 
rain according to the situation. If they fall through the pure air of 
tke country the raindrops will give feeble currents; if through the 
smoke-laden atmesphere of our towns they will have absorbed some 
of the sulphurous acid which is always present, and the action will 
be stronger. In either case its effect will be to dissolve some of the 
zinc, thus enlarging the rtneovered portion of iron, which at first may 
have been a mere speck, till sooner or later it reaches some branch 
that is tied to the wire and subjects it to the fatal influence of the 
electric current. Several of Mr. Wright’s facts tend probably to this 
explanation. He finds that—first, wire of the same metal throughout 
has no injurious effect (no galvanic action can here take place) ; 
secondly, more injury takes place near towns than in the country 
districts, because the rain contains acid in the former case ; thirdly, 
immunity is obtained by well painting the wire—the paint closes the 
perforations and prevents the action. The alleged existence of free 
acid in the body of the wire is curious. If it is there and escapes in 
the manner stated, it would in doing so act more readily on the zinc 
than on the iron, and would thus produce the perforations in question. 
But independently of their being produced in this way, one would 
quite expect to find them, as zincing depends only on mechanically 
moistening the surface of the iron, which is itself far from homo¬ 
geneous. Lastly, the almost passive condition which zinc assumes 
after exposure as compared with its chemical activity when bright 
and clean, would seem to account for old wire being harmless in cases 
where new would do mischief.” 
This is a very interesting letter, but whatever force the ob¬ 
servations may have generally, they do not apply to the above- 
mentioned experiments, which, with four Vines out of the five, 
“not a drop of water” was applied to the wires. The Vines 
are grown under glass, and there is no leakage from the roof. 
In purchasing new galvanised wire any that will not bend 
freely should be rejected. Unpainted and pliable wire may 
probably be safely employed in country districts where the air 
is pure, provided the wire is placed in water for a week before 
it is used for the extraction of any acid it may contain ; but 
near towns and in manufacturing and mining districts the new 
wire cannot be regarded as safe if it is not well painted. 
I wish to add that I have had the counsel of Dr. Hogg 
throughout this investigation, and I am indebted to him for 
valuable hints and suggestions in endeavouring to render an 
important and difficult subject plainer than it was before.— 
J. Wright. 
Garden Refuse. —The articles on this subject that were pub¬ 
lished in your last volume were most timely, and another brief 
note will perhaps not be unacceptable. The accumulation of 
rubbish from various sources in different departments in a large 
