24 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 
a thousand Roses, but a saving in time and labour was effected as 
well.* 
Again, with regard to Aster mildew, adopting the same method, 
two ounces of liver of sulphur sufficed in 191 5 for the Wisley collection 
of Asters, which comprises 130 plants, a very considerable reduction 
on the quantity used in 1914. This effective use of liver of sulphur 
when employed much more dilute than usually recommended is 
important, for it renders a great range of varieties, whether of Roses, 
Gooseberries, Asters, &c, amenable to treatment without risk of damage 
to the foliage by the fluid. (Fig. 5.) 
Burgundy mixture, consisting of sulphate of copper and sodium 
carbonate, which possesses, when properly mixed, remarkable natural 
adhesive features, is as invaluable for preventive as liver of sulphur 
mixtures are indispensable for curative purposes. One application 
of Burgundy mixture without any additional ingredient was sufficient 
to prevent almost entirely the occurrence of Exoascus leaf blister in 
Peaches and Nectarines at Wisley in 1915, and a still more remarkable 
case occurred at Brentford in a garden where a score of Peach trees, 
including both young and old neglected specimens, which had every 
leaf blistered and produced no fruit in 1914, were completely free 
and bore fruit in 1915 after receiving similar treatment. Burgundy 
mixture was also successfully used by squirting down the haulm to 
check the potato collar-rot fungus, Hypochnus Solani, and against 
Septoria Petroselini var. Apii, the cause of celery leaf-spot. In some 
cases the plant we desire to treat possesses some peculiarities : it 
may be coated with hairs, a waxy film, &c. The mixture has then 
to be adapted to the special conditions. Thus Burgundy mixture 
rolls off the foliage of Carnations in droplets; here a modification 
has been devised to bring the Burgundy to adhere to the plant's waxy 
surface, and by coating the whole Carnation plant with an exceedingly 
fine film of the preparation it can be effectively protected from infec- 
tion by Carnation rust (Uromyces Caryophyllinus). This modified 
Burgundy was employed on Delphiniums against Delphinium mildew 
(Erisyphe Polygoni) in greatly reduced strength without losing 
efficiency ; and here again, owing to the degree of dilution, the whole 
collection could be treated without damage to the foliage. 
Among newer remedies, formalin is sometimes advocated as a 
cure for mildew. Using the strength generally recommended for Rose 
mildew, on Gooseberries at Wisley, it proved of little value. Recently 
M. A. Blake and C. H. Connors f find that strengths really noxious 
to Rose mildew are harmful to certain varieties of Roses — for example, 
* The following is the formula of the wash used successfully in 1915 : — 
Liver of sulphur \ ozj 
Soap powder . . . 1 oz. 
Water i 1 gallon, 
f M. A. Blake and C. H. Connors in New Jersey Stn. Rep. 1914, pp. 38, 
39. These authors used strengths varying from 1/100-1/300 on 'American Beauty ' 
successfully, but found 1/250 disastrous to * Killarney.' 
