100 THE TROPICAL AGRICULTURIST. [Awn. 1, 1901. 
DISEASE IN PLANTS, 
WheQ a doctor is summoned to the bed-aide of a 
patient, he listens attentively to the narrative given by 
the side niau or his friends, forming meanwhile his 
own general impressions from the aspect of the patient, 
and from what he sees and hears. These preliminary 
proceedings are generally quite inadequate, and, bo 
far as the account and esneoially the theories framed 
by the patient are concerned, almost always mislead- 
ing if not wholly incorrect. Having gained as much 
information as possible in this way, and having made 
the necessary allowances, the doctor proceeds to inves- 
tigate " the case " for himself. He learns all he can 
about the family history, mode of life, and •' constitu- 
tion '' of his patient ;■ what previous illness he may 
have suffered from ; when, and in what manner the 
present sickness began, and what has been its progress. 
Having thus obtained a general knowledge of the state 
of affairs, the doctor proceeds to investigate, in due 
and regular sequence, the condition and working of the 
several organs of the body. And not till he has made 
this through investigation of " signs " that he sees 
and can personally detect, and of " synitoma" that are 
made known to him by the patient, does he venture on 
either diagnosis, or prognosis ; still less, unless he be a 
quack, on methods of treatment. 
Nether the patient nor his friends desire, or could in 
most cases appreciate, the inductions that the doctor 
makes. They wish to know, in general terms only, 
what is the matter, what are the prospects of recovery, 
and what are the measures to be taken to secure that 
•nd. , , , 
Plant doctors up to this time have been too communi- 
cative, and not sufficiently practical. If they see a 
fungus they forthwith measure its spores in fractions 
of a millimetre, they compare it with other organisms 
of a similar nature, and they draw up a highly techni- 
cal description, which is quite unintelligible and 
equally useless to the persons for whose benefit it is 
supposed to be framed. Now, we are far from wishing 
to depreciate these proceedings. For purposes of 
scientific research they are absolutely essential. It is 
likewise essential that the fungi be cultivated by the 
plant doctor, and their life-history accurately studied, 
as uDon the information so obtained depend in most 
cases our methods of combating disease or preventing 
its onset. This cultivation takes time, and hence it is 
not always possible to give an immediate or even a 
speedy answer to enquirers. But the details to which 
we have alluded are appropriate only to the student. 
The busy cultivator has not the time nor the means 
to make the necessary investigations. He wants 
general results, and specially indications for treat- 
ment. . . A 
Many, perhaps we may say most, treatises and papers 
hitherto written have been drawn up by experts, with 
too little attention to the requirements of cultivators. 
A book now before us proceeds to a large_ extent on 
different lines.* The very title, " Disease in Plants " 
(the italics are ours), indicates this. No one is more 
competent to compile such a book as this than Prof. 
Marshall Ward. The work is apparently based on 
a series of lectures, though we are not expressly told 
so ■ nevertheless, the following passage shows the 
intention of the writer ;— " The purpose of these 
essays ps to treat the subject of dissase in plants with 
special reference to the patient itself, and to describe 
the symptoms [signs] it exhibits and the course of 
the malady, with only such references to the agents 
which indnce or cause disease as are_ necessary to au 
iutelligent understanding of the subject, and of the 
kind of treatment called for," The first part is devoted 
to an admirably clear and concise a''COunt of the 
living plant and what it does, to th'i biology of the 
soil— a comparatively new but most important subject, 
and to a short account of hybridisation and seieo- 
tiOD. 
* Diacaife in Plants. By H, McH'shall Ward, Sc. D. 
(MactHillaa & Co.) 
Part II. is devoted to diseases in plants, their causes, 
nature, diffusiou, and the remedial measures to be 
adopted. Sundry chapters are given to " symptoms " 
of disea'se. which in medical pliraseology should be 
" signs, " and these should be attentively read by cul- 
tivators. The inclusion of scale-insects among symp- 
toms seems rather incongruous, but this is a matter 
of little moment. "Silver leaf "disease, characterised 
by the detachment of the ejndermis from the sub- 
jacent tissues is, in our experience, confined to mem- 
Ijers of the Ilosaceas, and is as common out-of-doors 
as under glass, so that we do not think it has any 
special connection with hot summers. Not only are 
plants considered in their medical aspects, but their 
surgical injuries ai-e also discussed, such as wounds 
of various kinds, including the burrowing excavations 
made by certain insects in leaf or branch. Among 
excrescences wa do not find mention made of the warta 
on the under surface of Vine-leaves, which are bo 
common ia vineries where the proper balance between 
temperature, moisture, and ventilation is not main- 
tained. Under " Gummosia," we do not find any r&- 
fcrance to Beijerinck'a observations on Coryneiim. 
The chapter on Life and Death is full of sugges- 
tive matter; the more so, as we know of hut one book 
intended for the use of cultivators that deals with this 
subject, and in that only in a much leas complete 
m inner than in Prof. Ward's book. 
The book has copious references to th« literature 
of the subject, but these are not always sufficiently 
explicit ; for instance, to cite the Gardeners' Chronicle 
without specifying the date of publication and page, ia 
simply to embarass the enquirer. The author has 
evidently been hampered by his desire to keep the book 
within convenient limits, a circumstance which has 
led to undue concision ; but, on the whole, we have 
nothing but praise to bestow upon a book which will 
be so useful to the intelligent cultivator that no 
garden library should be without it. — Gardeners' Chro- 
nicle, IVIay 18. 
MOSQUITOS AND EUCALYPTUS. 
The Bi-iiifsh Med'usal Journal doubts the 
wisdom of the proposal by the Sanitary 
Departinent of Havana to plant eucalyptus 
trees in all the marshy and mahirial districts 
in and around Havana as a mosquito de- 
terrent. The Journal in question points out 
that in a paper by Prof. Celli, which ap- 
peared in the Journal of the Sanitary Institute 
tor January, that distinguished authority 
says that the eucalyptus, so far from bein^ 
protection, is, like other trees, rather a 
shelter for mosquitos, and in the neighbour- 
hood of dwelliiif^-houses adds to the danger 
of malarial infection. — Globe, June 7. 
CEYLON VERSUS BAVARIAN 
GRAPHITE. 
This mineral, which is now much in request 
as a lubricator of maehinery, is one of the iiiosb 
valuable products of Bavaiia, the only formi- 
dable conipetiior in the supply of natural graphite 
bein;4 Ceylon. The production of grapliiie in 
Cyylon has, however, diniiiiinished, causing a great 
rise ill prices, as the deficit could not be made good 
from other sources. The Bavarian graphite is 
inferior to the Ce^lon product, as, while tlie 1 icter 
is neirly pure, the former has about sixty to 
seventy-five percent, ofeaitliy substances mixt'd 
with it. VVith Bavarian methods, it is stated, 
there is a great waste <i taw material, and it is 
alleged that nearly ninety per cent of the mineral 
is absolutely thrown away, owing to the short- 
sighted and unscientific system of workiag,— ^ 
United JStafcs Consular Report, . 
