August 17, 1893, ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER, 
143 
the Vine. Similar experiments carried out in Belgium, in America, 
and at the Cape of Good Hope have, the reports say, been 
“ favourable without exception.’' 
In 1892 the Board of Agriculture published a “ Report on 
Recent Experiments in Checking Potato Disease in the United 
Kingdom and Abroad,” which has been reviewed favourably in the 
“ Home Farm ” part of the Journal of Horticulture. In this 
“ Report” there is considerable difference in the results, some being 
highly satisfactory, and others “ worse than the disease ” on account 
of the damage to the crop and consequent depreciated yield. That 
is a point we will consider presently, but I wish to impress the fact 
on those anxious to save their crops from fungal attacks that there 
is no necessity to smother the leaves of the plants by coating them 
on their under sides with sulphate of copper. The spores of the 
Potato fungus enter the Potato leaves mainly by the stomates, 
therefore it has been concluded that the copper should be mainly 
placed there. This is a mistake, for M. Schloesing’s experiments 
show that the copper is retained by the cuticle of the leaves, and 
its retention by the upper surface of the leaves is sufficient to 
prevent the fungus from establishing itself upon the under sides, 
where it first invades the Potato plant, and finally descends to 
the tubers. This is important, because it renders applications 
made after the disease has been established effective in staying 
the attack and considerably increasing the crop by preserving 
the vigour of the plants to a much later period than would be the 
case were they not treated. Copper, therefore, is a preventive and 
curative agent in the treatment of the Potato disease. 
The reason why some mixtures of copper sulphate have 
proved innocuous to the foliage of Potatoes, whilst similar have done 
it considerable injury, is solely due to a proper or improper mixture 
being employed. If the mixture contains no free copper, and is not 
too strong, it will not do any harm whatever to the tenderest foliage, 
but if it comprise the least moiety of free copper it will blacken 
every leaf it is sprayed upon in degree corresponding to the amount. 
Chemists are remiss in not telling us all about this ; perhaps they 
think everybody knows as much as they do, or that only they have 
the right to know anything of the why and wherefore. Every 
schoolboy will know all about these things shortly. A correspondent 
last year noted in the Journal of Horticulture that his preparation 
of Bordeaux mixture was brown in colour, which is not unlikely, as 
much of the so-called sulphate of copper is largely adulterated with 
iron sulphate, still he found it efficacious as a fungicide ; hence I 
conclude, rightly or wrongly, that it contained next to none of 
sulphate of copper, otherwise it is impossible to account for its not 
laying the plants to which it were applied dead and prostrate, for 
the brown colour of a copper solution is a clear indication of its 
not being neutralised by the lime. Chemists have an infallible 
test for the free copper in a Bordeaux mixture, namely, ferro- 
cyanide of potassium, and it was first mentioned by Dr. G. 
Patrigeon in the “ Journal d’Agriculture,” Prat. No. 54, page 701. 
Half an ounce of ferrocyanide of potassium is dissolved in 2 or 
3 ozs. of water, placed in a bottle and kept corked. It is not 
poisonous, and is a solution of the commonly called “ red prussiate 
of potash.” When it is desired to test the Bordeaux mixture for 
free copper a few drops of this solution is added, and if the mixture 
contains the least quantity of free copper it immediately gives 
a brownish reaction. Such mixture is not safe to use upon 
any plant, for it will blacken Potato tops, Tomato leaves, every 
thing. If there be no reaction when the ferrocyanide solution 
is added, the mixture or solution contains no free copper, and 
is perfectly safe to apply to any plant, provided the dose is 
not too strong, for another reaction sets in afterwards ; therefore, 
the mixture should not be kept several days, but must be used 
after it is prepared, according to the formula given, as soon as 
possible. 
The American Bordeaux mixture always differed from the 
European in containing one-third less lime than of sulphate of 
copper, whilst the majority of the latter consisted of equal propor¬ 
tions of sulphate of copper and lime, the per-centage being 
calculated by the sulphate of copper relative to the water used. 
The bouillie Bordelaise used in the experiments carried on by the 
Royal Agricultural Society of England for the Board of Agricul¬ 
ture in 1891 consisted of 20 lbs. of sulphate of copper, 10 lbs. of 
unslaked lime, and 100 gallons of water. M. Girard frequently 
used a 2 per cent, bouillie—that is, 20 lbs. of sulphate of copper 
and the same of lime to 100 gallons of water. M. Thienpont 
thinks a 2 per cent, bouillie better than one of 4 per cent., and 
strives to hit a happy medium between his and M. Girard’s 3 per 
cent, recommendation by a 2^ per cent, bouillie. M. Petermann 
tried a 1 per cent, mixture, and recommended a 2 per cent. one. 
The United States bouillie varied from a 2 to 2| per cent, of 
sulphate of copper. All have reference to the Potato disease.— 
G. Abbey. 
(To be continued.) 
A DOUBLE MONTBRETIA. 
Mr. W. Bain, gardener to Sir Trevor Lawrence, Bart., Burfoni 
Lodge, Dorking, placed a novelty before the Floral Committee of the 
R.H.S. on August 8th in the form of a double Montbretia crocosmaeflcra, 
and its value and distinctness were recognised by a first-class certificate. 
Sir Trevor had it from the Continent, but Mr. Bain is unable to give 
any information as to its origin. Strictly speaking the form is semi¬ 
double, but the flowers are well filled, and in colour they are bright 
orange yellow. This promises to be a valuable addition to a useful 
class of plants. None of the Montbretias at present receives the 
attention it deserves. M. Pottsi, M. crocosmaeflora, and others are 
exceedingly useful from their free flowering nature, their distinct 
colours, their long period of beauty, and their ease of culture. The new 
variety which fig. 21 represents will serve a good purpose if it draws 
wider attention to the whole genus. 
CADLAND PARK. 
Among the many fine estates that are situated on the shores of the 
Solent Cadland Park stands out prominently. It is the seat of Andrew 
Drummond, Esq., of the well-known banking firm at Charing Cross, and 
is about three miles from the pretty village of Hythe, and seven miles 
by water and land from Southampton. To reach the mansion anil 
gardens from the southern seaport town is a matter of taste for the 
visitor. Those who prefer a short but enjoyable sea trip can “ cross the 
stream,” as termed by the local “salts,” by steamboat in about twenty 
minutes from Southampton to Hythe, starting from the town quay, 
which is within a short distance of the railway stations. On a fine 
