86 
BOTANICAL INDEX 
Baron von Mueli.kr writes under date of March 18th: “Why do you not fin 
America) plant Eucalyptus Mill ion fold to subdue yellow fever? You ought to raise 
our quick growing Acacias in large masses. They grow twice as quick as the best 
oaks, and give three times as much tannin.” (There is no doubt that we in America 
are not making the progress in introducing many of the most desirable trees and 
plants for economic purposes, that some of the newly settled portions of the world 
are doing; but there is only a small portion of our country where the climate would 
warrant an extensive effort at cultivation of many of the most desirable things. It 
must be borne in mind that the climate on our Atlantic coast is always several de- 
grees colder than that of Europe on the same parallel of latitude, caused by the gulf 
stream flowing north, — i.e., from the equator, past Europe, but south, or from the 
Arctic region, past eastern North America. There is quite an interest, however, in 
Eucalyptus planting in our Southern States and California, and as time demonstrates 
the sanitary benefits derived from these'trees, no doubt they will be more generally 
planted. The city of Memphis, which ha> suffered more severely than any other 
from yellow fever, is probably too far north for Eucalyptus to survive an ordinary 
winter, wlple the occasional severe winters wquld be very sure to destroy them.) 
ELECT HI CITY ANI) HORTICULTURE. 
Dr. Siemens has just read before the Society of Telegraph Engineers in London a 
paper on the recent applications of the dynamo-electric current to metallurgy, horti- 
culture, and the transmission of power, in which he gives the latest results of his 
investigations and experiments on this subject. lie described an electric furnace 
which he says is more economical than the ordinary air furnace, and which, so far as 
economy of fuel is concerned, is nearly equal to the regenerative gas furnace. Be- 
sides other advantages claimed for it, it is capable of an almost unlimited degree of 
heat. Successful experiments with the apparatus matte by the lecturer in the pres- 
ence of the critical audience were “hailed with ringing cheers.” Dr. Siemens’ 
latest investigations confirm the announcement made some time ago concerning the 
value of the electric light in horticulture. lie has reached the conclusion that elec- 
tric light produces the coloring matter chlorophyl in the leaves of plants, helps 
growth, counteracts the effects of night frosts, and advances the setting and ripening 
of fruit in the open air. Not only do plants need rest during the twenty-four hours 
but their growth may be materially advanced by exposure to sunlight during the day 
and to electric light during the night. At least, tins is the result of experiments 
carried on during certain short periods. And this conclusion is in harmony with 
what Dr. Shubeler found in Norway, namely, that in the prolonged daylight of 
northern summers plants produce more brilliant flowers and larger and more aroma- 
tic fruit than are seen in more southerly countries where the lightness of day and 
darkness of night are about equal in duration. Dr. Siemens having found that 
plants under the influence of electric light can stand additional heat, expresses the 
opinion that forcing can be grown without immediate solar help. Dr. Siemens has 
made extensive preparations for experimenting on a working scale at his farm next 
winter. Among other questions which lie wishes to determine is which part of the 
rays constituting white light produces chlorophyl, starch and woody fibre, and 
which part causes the fruit to ripen. — Exchange. 
PARAFFIN OIL AND MEALY BUG. 
I have used this oil for these last three years with the most satisfactory results, 
and would much rather have it than any other insecticide. Two years ago mealy 
bug attacked our Vines, and the ensuing winter I brushed, with an ordinary paint- 
er’s brush, the canes over with a mixture ot this oil and water before I gave them 
the usual painting. No harm whatever was done to the eyes, and the insects were 
exterminated. Whenever I see a bug I apply the brush, which seems to act like 
magic. I use the oil generally for all plants (except soft Ferns or such like), taking 
care of any soft shoots and leaves which may happen to be on the plant, and in con- 
sequence I am able to keep any plants which I have freer from insects, with much 
less trouble and expense, than heretofore; for, as “T. B.” rightly says (p. 853), the 
various insecticides used hitherto become somewhat costly when they have to be 
bought in quantity, and they likewise require more time to make them up for use. 
I would recommend it, as I have already done, to all who are troubled with that 
worst of pests — mealy bug. Thrips and aphides can lx* easily overcome by means of 
fumigation, but for mealy bug and scale a touch with the brush dipped in a proper 
mixture of paraffin oil and water at once becomes their deadly enemy and the gard- 
ener’s friend. — S. K. in The Garden. 
