42—1846.] 
THE GARDENERS' 
CHRONICLE. 
691 
ECK’S, HOYLE'S, MILLER’S, AND FOSTER’S 
Purchaser's selection, 31.—BECK’S Mare Anton; uno, Des- 
demona, Rosy Circle, Sunset, Isabella, Margaret, Zenobia, 
Mustee, Bellona, Arabe avorita, Bella. —HOYLE'S Au- 
rien new varieties at ll. 1s. per dozen. 
"Geranium Catalogue, which can be had gratis. 
Hybridized Geranium Seeds, 100, 10s.; 50, 5s. ; 25, 3s. 
WirrrAM MILLER, Providence Nursery, Ramsgate, 
ROSE CATALOGUE. —NEW EDITION. 
NURSERIES, CHESHUNT, HERTS. 
PAUL anp SON beg to apprise their friends and 
* the publi New Edition of their ROSE 
CATALOGUE is now ready for cirenlation, and which will be 
See printed 
T BECK informs the Public that the various Articles 
* manufactured by him in Slate for Horticultural pur- 
poses, may be scenin use at Worton Cottage, Isleworth, upon 
application to the gardener (Sundays excepted). i 
The Gardeners’ Chronicle, 
SATURDAY, OCTOBER 17, 1846, 
No visible cause for the Porato pisEAsE having 
beén discovered, or at least found satisfactory, men 
have naturally taken refuge in the invisible. It is 
so easy to test theories built on the action of agents 
which may be seen if they exist, that persons with 
speculative minds have always been fond of seeking 
refuge in the regions of imagination. Hence have 
arisen sundry hypotheses about electricity, meteors, 
deranged luminosity, and smells too subtile for the 
nose ; which, if they are incapable of proof, have 
the great advantage over more material causes, 
that they are equally difficult of disproof, 
In studying such transcendental views, we must 
by no means omit the name of Mr. Tuomas Cnorr, 
who, it seems, is the author of “the” Chemico- 
agricultural Essays. This gentleman has made the 
Pennsylvanian world acquainted with his opinions 
in a pamphlet which has the following attractive 
title :—“ A Philosophical and Practical Treatise on 
the Potato Disease, recommending a remedy for it, 
‘Which, when properly applied has, in hot or cold, 
wet or dry, clayey or sandy soils, invariably cured 
or prevented it ; also showing that the cause of the 
disease, when great, may be so directed as to largely 
increase the crop of healthy Potatoes." 
In this country men would have had glory 
enough in showing how the cause of the disease is 
to be removed ; but Mr. Crorr does more, he tells 
us how to make it profitable. We at once concede 
that this is a step far in advance of anything that 
we have heard of on this side of the Atlantic. 
Mr. Cnorr has discovered that “an excess of 
carbonic acid" is the cause of the mischief, He 
does not say how he knows it to beso; he does 
not furnish us with any evidence of the fact ; but 
he asserts it, which is the same thing—in his own 
opinion. 
Having thus discovered, that is to say asserted, 
that carbonic acid causes the evil, Mr. Cnorr, by 
aid of his chemical knowledge, points out a cure. 
* An excess of carbonic acid causes the Potato dis- 
ease, and the alkalies are the proper remedy for 
it ;” that is his opinion, It appears, however, that 
the caustic alkalies are not necessary to effect this 
cure ; their salts will do as well, And accordingly 
we find Mr. Cnorr resting his proof upon the sup- 
posed action of sea-salt and “lime prepared ma- 
nure,” that is to say of manure in which the lime is 
in the form of a carbonate, and the soda of a 
muriate. 
Let it not, however, be assumed, because Mr. 
Cnorr writes from Dreamland, that. all hypotheses 
of the Potato disease being caused by some un- 
known miasm are equally unworthy of considera- 
tion. As we have frequently stated we by no 
means at present accept such an explanation as 
satisfactory; but neither can we entirely reject 
it, considering how signally all others have failed. 
'The disease maybe of the nature of cholera; it 
may be an epidemic affection analogous to the cattle 
murrain, which certainly would seem to be of such 
a nature; and we have no desire to treat with the 
slightest disrespect those who have come to that 
conclusion, We only say that their arguments are 
at present unsatisfactory, and that the hypothesis 
does not appear to meet the case in some im- 
portant particulars. 
We will not insist upon the objection to the 
theory of miasm that we have no modern well- 
attested instance of epidemics attacking plants, for 
s: : E 
it is possible that they may nct kave boen obsez od, parkin, 8vo. pp.198. Hatchard, 
and it is doubtful philosophy to assume that the 
principle of vitality is distinct in the vegetable and 
animal worlds ; modern science points indeed to the 
opposite conclusion, and ancient testimony seems to 
be in favour of the opinion that plants are subject 
to epidemics. This doctrine was maintained with 
cated from subterranean reservoirs becomes inno- 
cuous when largely diluted in the atmosphere.” 
Such is Mr, Parxry’s view of this matter, as far 
as we have space to explain it. His book should 
be studied. In considering how far his views are 
great ingenuity by Mr. Parrin, in his work on 
Epidemic Diseases* published five yearsago. He 
observes :— 
“ That the cause of pestilence exists in the atmo- 
sphere, would also appear from the fact, that at all 
epidemic periods vegetable life is affected, as well 
as animal. Hence, as Webster has remarked, pes- 
tilence, murrain of beasts, and famine occur at the 
same time. We find this to have been the case in 
the earliest record we have of pestilence ; for it is 
said in scripture, that the plague of blotches and 
blains, the murrain of beasts, and the blight pro- 
ducing famine in corn, all visited Egypt in close 
succession. The same circumstance was observed 
in the black death of the 14th century, as we have 
before shown, while considering the atmospherical 
changes and vicissitudes which occurred at this 
period: for although there was an abundance in 
the granaries at the commencement of the plague, 
failures in the crops became so general, subse- 
quently, that children died of want.in their mothers’ 
arms, 
* That the famine in these cases is not the cause 
of the pestilence is certain, from the fact, that 
plagues have frequently commenced in the midst of 
the greatest plenty ; while famine, when it occurs 
at epidemic periods, follows the disease in the gene- 
rality of cases. This shows, that vegetables are 
able to resist the malign influence, which produces 
disease, for a longer period than animals. ‘That the 
destruction of vegetable life is produced by the same 
cause as that which gives rise to disease and death 
among animals and the human species, we may 
infer from the fact, that the same peculiarities are 
observed in the one case as in the other. Thus 
blights, like epidemic diseases, are only observed 
along particular lines of the earth’s surface ; for 
so defined is their boundary, that they will not only 
intersect a field, but they will even attack one side 
of a tree, and leave the opposite untouched. That 
the cause, productive of these effects, cannot exist 
generally in the atmosphere is clear from the limi- 
tation of its operation to such narrow boundaries. 
It is only on the supposition that some poisonous 
element is extricated from the soil along the lines 
taken by the blights themselves, and which becomes 
innocuous ata certain distance from dilution in the 
surrounding. atmosphere, that will enable us to ac- 
count for the effects observed. But the poison, 
although extricated on the surface, cannot be pro- 
duced from any peculiarity of soil, as. this is found 
to. have no influence on their direction or limita- 
tion; for blights are frequently seen to extend 
along a line only of some particular district, the 
geological and other features of which are exactly 
the same. 
* Again: These diseases of vegetables, like those 
which attack animals, frequently spring up in some 
particular district, where, previously, they were 
unknown; continue to prevail for certain definite 
periods, and then subside. Thus it has been stated 
by some writers, that Wheat had not been known 
tomildew in France until the year 1550—an epi- 
demie period, and that in which the black death 
prevailed in Europe. Webster also informs us, 
that it has been impossible to raise Wheat in Mas- 
sachusetts since 1664, on account of the mildew— 
although it was successfully produced by the first 
settlers in that country. As these affections of 
vegetables are only observed at particular epochs, 
although the soil, and all other external circum- 
stances remain the same at other periods, to a cause 
existing beneath the surface we can alone look for 
the generation of the poison productive of these 
effects among vegetables, the same as animals. This 
cause, if the deductions before drawn are correct, 
must be that usually designated volcanic action, as 
we know of no other process which could give rise 
to the same effects,” 
Volcanic action, in Mr. PAnxiN's opinion, causes 
cholera, and those other mysterious affections which 
man has so entirely failed to deal with successfully. 
He believes that all cases of the kind are so far 
traceable to. the neighbourhood of lines of voleanic 
disturbance that the latter offers an intelligible ex- 
planation of their appearance ; and that it is the 
only satisfactory solution of the curious facts 
that cholera travels against the wind as well as 
with it, and that its action is often confined to one 
side of a street or road, or to a narrow strip of 
country, without reaching the neighbourhood, a 
i t which he i explicable upon 
the supposition that *the poisonous matter, extri- 
* On the remote cause of demic Diseases, By John 
pplicable to the present disaster the reader cannot 
fail to be at once struck with the fact that the 
disease travelled in 1845 westward from Poland 
to the West of Europe, extending in it: most 
northerly courseto Christiania, bending downwards 
as low as Aberdeen and losing itself in the West of 
Ireland, while to the south it formed a line: drawn 
from Lyons through Bayonne to the north of 
Portugal, missing, however, the Spanish province of 
Galicia. The whole of the Mediterranean was free 
from disease. It is for geologists to decide how 
far this is consistent with lines of volcanie forces. 
The absence of the disease from the Mediterranean 
might, perhaps, be accounted for by the activity of 
the volcanoes there, which allow gaseous matter to 
escape by their natural vents, while in countries 
where such vents do not exist gases are pent up 
and must escape through subterranean interstices 
of which there is no indication on the surface. 
Supposing that Mr. PanxiN's theory should not 
be inconsistent with geological facts, concerning 
which we are not prepared to express an opinion, 
this great difficulty will remain. The disease ap- 
peared in Bermuda, exclusively among imported 
Potatoes; Bermuda is a coral reef, and its Potatoes 
were sound, except where the seed was obtained 
from the United States. In like manner the disease, 
at Oporto and Graham's-town, is reported to have 
been confined to crops raised from English imported 
sets. How these facts are to be reconciled with 
the volcanic theory we do not discover. 
We wish we could satisfy ourselves. that Mr. 
Parkin is right ; because if so we might hope that 
the disease is already disappearing, and would wear 
out sooner than we at present anticipate. It is cer- 
tainly less formidable in France and Germany and 
the south of England; but that may have been 
owing to the fine summer, which enabled the 
Potato crop: better to withstand the evil when it 
came; while in Ireland and North Scotland the bad 
habits of late planting produced the opposite effect. 
Many other difficulties suggest themselves, but we 
must not occupy more space to-day with these spe- 
culations, which we now lay before our readers for 
their own consideration rather than for our dis- 
cussion. 
We learn from the Daily News that Mr: Justice 
Torrens has announced that he will give premiums 
to his tenantry, on all his estates in Derry and else- 
where, for the cultivation of Rye. Mr. Josrick 
Torrens has done well, and we earnestly hope that 
his example will be followed, either exactly, or by 
the Irish gentry taking the most active measures to 
secure the cropping of land with something that 
may certainly be gathered in, 
We have formerly pointed out the relative value 
of various substitutes. for the Potato. (see p. cA 
and we again refer to the information there col- 
lected. But in the present state of Ireland nothing 
can be universally employed in room of the Potato 
except grain, because there is no possibility of 
procuring the requisite quantity of seed for any 
other field crop. Mr. E. B. Rocme stated a few 
weeks since that he had ascertained the fact that 
3000 acres of land were this year under Potatoes 
in one Union (that of Aghada) and a writer in the 
Cork Reporter asserts that 130,000 (Irish) acres 
are so cropped in the county of Cork. Now if it 
were proposed to substitute Carrots in these cases, 
it would require nearly seven tons of seed for the 
parish, and 380 tons for the county ; or 1786 tons 
if we take all Ireland. Such quantities are not 
procurable. 
If half-a-dozen different substitutes, not grain, 
were selected for cultivation, the difficulty would 
be of course diminished, but not removed ; for the 
European seed market is only supplied with what 
suffices for ordinary consumption, and is wholly 
unable to meet any vast unexpected demand. 
Grain and grain only must then of necessity be 
the crop mainly chosen to replace the Potato in 
the first instance. Provisions of another kind can 
only be introduced by degrees. We, therefore, 
repeat that the step taken by Mr. JUSTICE, Torrens 
is one of the most judicious that can be made under 
the present circumstances of Ireland, 
———— 
BRITISH ASSOCIATION FOR THE ADVANCE. 
MENT OF SCIENCE, 
(Continued from p. 677.) : 
Furpay, Sept. 11.—In the natural history seetion a 
paper was read from Mr, Beysamin CLARKE, “On the 
foliage and inflorescence of the genera Phyllanthus and 
Xylophyllum.” The author stated that the leafy áppen- 
dages from which the flowers in most of the species of 
these genera spring have been described by De Candolle, 
