en 
‘on to sensitised paper, 
DeEcEMBER 17, 1896] 
NATURE 
55 
be glad of information as to the best method of working direct 
to save the time and expense involved in 
taking glass negatives. G. M. Lowe. 
Lincoln, December 7. 
“ Chelidonium majus” as a Cure for Cancer. 
Wuiru reference to the probable value of Chedidonzwm majus 
in the treatment of cancer, I beg to enclose the two following 
extracts from ancient writers for the purpose of showing that its 
value, for internal use, was not unknown. 
In the ‘‘Ortus Sanitatis,’ of J. A. Cuba, published at 
Mayence in the year 1491, he makes the following remark, 
inter alia, upon the property of this plant. 
‘© Et ad cancrum oris pulvis radicis cum pulyere rosarum con- 
ficitur, et cum aceto decoquitur.” 
Again, Bodeeus a Stapel, of Amsterdam, in his edition of the 
“Jlistoria Plantarum” of Theophrastus (1644, p- 894), after 
describing the method of preparing a decoction of the plant, 
says :— 
x Primi liquoris seu elementi aquei usus existimatur, quod 
intra corpus sumptus, omnes humores corruptos et perniciosos 
corrigit et educat.” 
Barton and Castle, in their ‘‘ Flora Medica” (1838), remark 
that “ Linnzus, Murray, Gilibert, and others express their 
astonishment at the oblivion into which a plant so energetic as 
the Celandine has fallen, while the ancients knew how to ap- 
preciate its qualities.” C. LEESON PRINCE. 
. The Observatory, Crowborough Hill, Sussex, November 26. 
Measurements of Crabs. 
Tue crabs measured by Prof. Weldon, which’ “were “12°5 
centimetres long, had the ratio of frontal breadth to carapace 
length equal to 778°39 thousandths with a quartile deviation of 
10°79; the adult crabs had the above-mentioned ‘ratio 604°94 
with a quartile deviation of 9°96. He concluded that since 
9°96 is less than 10°79 the adults were less variable than the 
young, and that this diminution of variability might be accounted 
for by the selective destruction of those young crabs in which the 
ratio of frontal breadth to carapace length was much greater or 
less than the average. That Prof. Weldon was mistaken in 
making this inference may be shown thus :-— 
If he, in his investigations, instead of considering the ratio of 
frontal breadth to carapace length had considered its reciprocal, 
the ratio of carapace length to frontal breadth, he would have 
arrived at the result that those 12°5 centimetres long had a ratio 
of carapace length to frontal breadth amounting ‘to 1284°7 
thousandths with a quartile deviation of 17°9, while the adults 
had a ratio of carapace length to frontal breadth of 1653°1 with 
a quartile deviation of 26. This would have shown that the 
ratio of carapace length to frontal breadth was more variable (in 
Prof, Weldon’s sense of the word) with adults than with the 
young. This, he would probably have argued, may be due to 
the selective szvzva/ of crabs in which the ratio of carapace 
length to frontal breadth deviates excessively from the average. 
But those crabs in which the ratio of carapace length to frontal 
breadth deviates excessively from the average are precisely the 
same as those in which the ratio of frontal breadth to carapace 
length deviates excessively from the average, which latter he 
concluded were selectively destroyed. Thus the same reasoning 
applied to the same data leads to two totally irreconcilable 
explanations. Such reasoning must be false. 
Prof. Weldon’s erroneous conclusion seems to have arisen 
from making the mistake he accuses me of making, z.e. con- 
fusing variability (the quantity measured by quartile deviation) 
with importance of variability. Having proved that variability 
in the above sense of the word was less in the case of adult than 
of young crabs in regard to the ratio of frontal breadth to cara- 
pace length, he argues about the diminished variability as if it 
were the same as diminished importance of variability, which is 
in the general case measured by ratio of deviation to average 
amount of the quantity measured. J. A. Coss. 
Minneapolis, November 25. 
Diselectrification by Phosphorus. 
IN No. 1410, vol. lv. of NATURE, Mr. Shelford Bidwell refers 
to the discharge of electricity by phosphorus when it is oxidised. 
In a paper published by Prof. Naccari (Attd della Science di 
NO. 1416, VOL. 55] 
Torino, vol. xxv., February 22, 1890) as well as in one of our 
own ( Wdedemann’s Annalen, xxxix. p. 321, 1890), you will find 
a record of this observation. ELSTER AND GEITEL. 
Many thanks for sending me the above. I much regret 
that I did not know of the experiments referred to. I made a 
considerable search before sending you my letter ; but it is so 
difficult to ascertain what has been done before, that one hesitates 
to publish anything. SHELFORD BIDWELL. 
Riverstone Lodge, Southfields, S.W., December 2. 
Cultivation of Woad. 
LaTELy at Leighton Buzzard, I saw an old *book, ‘f E. 
Bowen’s Complete System of Geography, 1743,” in which some 
account is given of the growth and preparation of woad in 
Bedfordshire. There isa Woad Farm at Lathbury Bridge, near 
the confluence of the river Lovat, or Ouzel, with the Ouse, at 
Newport Pagnell, Bucks, and commented upon in the Backs 
Standard, November 8. The author [name not given], after 
referring to the more ancient growth of woad, gives it as his 
opinion that, ‘‘this once largely used herb was grown on this 
farm at a later period, and hence its name.” 
The lands of the Woad Farm are alluvial clay and river 
gravel, and there is an osier-bed in the locality. 
December, 1896. A. C. G. CAMERON, 
Dormant Seeds. 
Tue remarkable experiments of Prof. C. de Candolle reported 
on p. 21, and those formerly described of Prof. Giglioli, seem 
| certainly to show that life in a seed may be prolonged indefinitely 
under suitable conditions; or rather, that so long as no 
destructive change occurs, the power of living, not necessarily 
life itself, persists in the protoplasm. It has occurred to me as 
barely possible that some seeds from amber might be made to 
grow. It sounds a very wild suggestion, but the conditions of 
perfect preservation, with protection from air and moisture, are 
peculiar, and should offer as good a chance as some of those 
arranged by Prof. Giglioli, or cited by Prof. de Candolle. _ 
T. D. A. COCKERELL. 
Mesilla, New Mexico, U.S.A., November 19. 
The Arrangement of Branches of Trees. 
May not the want of symmetry or the ‘‘anyhowness ” of the 
arrangement of the branches of trees serve some highly useful 
purpose? May it not help to prevent the trees being overturned 
in the highest winds by the want of synchronism in the motions 
of the branches? I have never seen or heard of such an idea’, 
and it may be open to serious objections ; but some time ago IT 
watched the branches of a large plane tree, still partially in leaf, 
during a high gale, and it seemed incredible the tree could stand, 
but for the fact that whilst one large limb was swaying one way, 
another would be swaying the opposite way, and so on, all 
plunging and bending anyhow, with no two in harmony. Some 
of the larger limbs would swoop down as others bounded up in 
a sudden gust, and some swaying laterally with the wind would 
be balanced by others at another part of the tree swaying against 
the wind. 
The oak, the beech, the ash, and so on, have all this ‘‘anyhow- 
ness” of branch arrangement, they at the same time being our 
largest trees and most in want of it. 
Do the early stages of tree evolution point to a more 
methodical mode of branching ? THOos. SWAN. 
Maryfield House, Leslie, Fife, December I1. 
Curious Purple Patches. 
REFERRING to “‘ Purple Patches,” in NATURE of November 
12, Ihave frequently seen patches like those mentioned, but 
not quite so large, on the decks of ships immediately after they 
had been scrubbed with sa/f wafer. 1 have also seen them in 
bad weather at sea when salt water was coming over the side. 
I never remember noticing them after rain, or at any other time 
than when salt water has been on the decks. 
The idea I have always had, and heard others at sea speak of, 
is that they were small salt-water organisms squashed out by 
the foot. 
I have noticed them most frequently on the Scottish coast, 
but I have also seen them in China. Out here I have not 
observed them. E. 
Mediterranean Station. 
