73 
places where the soil is thin. In such places they are too short to be 
harvested. 
A very careful study of the plants has been made in the field and 
laboratory, but nothing in the way of a fungous or animal parasite that 
could cause the trouble has been found. From the nature of the dis¬ 
ease our attention has been directed mainly to a study of it from a bac¬ 
terial standpoint. Bacteria have been found in every specimen exam¬ 
ined. Nearly 200 cultures have been made in at least a dozen different 
media and all have yielded two germs, one of which is exceedingly abun¬ 
dant. In nearly 50 cases the disease has been produced in young 
pot-grown plants by inoculating from direct material. Inoculations of 
young plants with pure cultures are now under way and it is hoped 
that some definite results will soon be obtained from this source.* 
There is still a possibility that although the disease may be caused 
by bacteria they are dependent upon certain conditions of the atmos¬ 
phere for their development, and need not be feared another year. Ex¬ 
periments to settle this question are also under way. 
COPPER-SODA AND COPPER-GYPSUM AS REMEDIES FOR 
GRAPE* MILDEW. 
By J. Nessler. 
(Translated from Biedermann’s Centrall-Blatt for April, 1890, by Gerald McCarthy, N. 
C. Experiment Station.) 
For several years preparations of copper-soda and copper-lime have 
been employed for mildew of the grape with good success. Neither of 
these preparations do any injury to the sensitive parts of the vine. 
The copper-soda mixture neither clogs the openings of the sprayer nor 
interrupts the spray by foaming ; moreover, it sticks to the leaves very 
well. With this mixture the granular deposit is formed less rapidly the 
first day, but after that more rapidly than is the case with the copper- 
lime mixture. Sulphate of copper is decomposed equally well by soda 
and by lime. The granular deposit takes place sooner or later, accord¬ 
ing to the method of preparing the mixtures. Once formed, the pul¬ 
verulent mass returns to its former state very quickly after being stirred, 
and on this account it is liable to clog the opening of the sprayer. More 
particularly is this the case when the lime used is not very finely 
divided or the copper solution is not sufficiently diluted. One should 
therefore use in mixing only a perfectly homogeneous lumpless lime- 
cream and copper solution so dilute that little or no additional water 
* Since writing this the disease has been produced in fifty or more cases by inoculat¬ 
ing with the more abundant organism. Five days after inoculating, the characteristic 
discolorations appeared, and cultures made from these have yielded the typical organ¬ 
ism in a nearly pure condition. 
