May 19, 1870 | 
NATURE 
43 
cites examples of trees which have been known for a great 
length of time. The discovery is usually attributed to 
Malpighi and Grew, who published their works, the former 
in 1675, the latter in 1682 ; it was, however, known earlier ; 
for Montaigne, passing through Pisa in 1581, learnt the 
fact from a jeweller of that town, in terms which recall 
those used by Leonardo, I transcribe the description of 
Montaigne :-— 
“The workman, an ingenious man, and famous for the 
manufacture of beautiful mathematical instruments, in- 
formed me that every tree bears as many circles as the 
years it has lived, and he showed me this in all the speci- 
mens of wood which he had in his shop. And the part 
which is exposed to the north is firmer, and the rings 
closer and more dense than the rest. By this means he 
professes to be able to judge of any piece of wood that is 
brought to him, both the age of the tree, and in what 
situation it grew.” * 
The following are the words of Leonardo :— 
“The southern part of the plant shows more vigour and 
youth than the northern. The rings of the branches of 
trees show how many years they have lived, and their 
greater or smaller size whether they were damper or drier. 
They also show the direction in which they were turned, 
because they are larger on the north side than the south ; 
and for this reason the centre of the tree is nearer the bark 
on the south than on the north side.” 
From this it will be seen that both the observations on 
the age, and those on the eccentricity of the trunks of 
trees, attributed hitherto by De Candolle + and others to 
Malpighi, had been previously made by Leonardo da 
Vinci. 
3. The growth of exogenous stems by the formation of 
new wood beneath the bark. This he describes in the fol- 
lowing sentence :— 
“The growth in the size of plants is produced by the 
sap, which is generated in the month of April between the 
outside coating (camzsta) and the wood of the tree. At 
the same time this outside coating becomes converted 
into bark, and the bark acquires new crevices of the depth 
of the ordinary crevices.” 
It will be seen that, although the painter correctly indi- 
cated the portion of the trunk in which the increase takes 
place, he nevertheless failed to detect the cambium, and 
the important part which modern researches have shown 
that it plays in the formation of new wood. 
For the above illustrations of the botanical knowledge 
of Da Vinci, we are mainly indebted to the article already 
named by Uzielli, who states that he might cite from 
the “Treatise on Painting” many other observations, 
generally correct, on the structure and development of 
plants, on the symmetry of their secondary axes, and on 
the influence which external agents have upon their 
growth. Uzielli remarks that it is strange that Venturi 
does not mention these botanical observations, he having 
had Leonardo’s MSS. for a long time under his hand, not 
even referring to them in his “Essay on the physico- 
mathematical works of Leonardo da Vinci,’ where he 
claims for the painter the character of a great savant, 
and one of the founders of the experimental method. 
Amoretti, and all the other illustrators of his life and 
Journal of Travels in Italy, by M. Montaigne. 
+ Organographie yégétale, vol. 1. p. 324. Paris, 1827. 
works, are also silent ; and Libri, who wrote after the 
publication of the Roman edition of the work on Painting, 
mentions only that Leonardo records in it some botanical 
observations, Libri was, however, the first to publish the 
important experiments of Da Vinci relative to the action 
of poison on plants, discovered in the MSS.* preserved in 
the Library of the Institute at Paris, in which he also 
alludes to an ingenious process of drying plants, and 
reproducing their form easily on paper. Not only these 
MSS., but those also in the Ambrose Library at Milan, in 
the British Museum, and at Windsor, and those to be 
found in some private libraries, would doubtless repay a 
more careful research than has at present been bestowed 
upon them ; and we would commend the subject to the 
attention of whoever takes up the thread of the life of 
Da Vinci, broken by the lamented death of Mr. B. B. 
Woodward. 
Sir Charles Lyell + refers to Leonardo da Vinci as one 
of the first who applied sound reasoning to the facts of 
Geology, and who taught the organic origin of fossils. 
His botanical and geological theories are alike evidence 
of the spirit in which he applied all the powers of his 
mind to the observation of the phenomena that sur- 
rounded him, and which prompted him to counsel his 
pupils and readers invariably to have recourse to Nature 
rather than to the works of man, as their guide and the 
source of their inspiration. 
ALFRED W. BENNETT 
THE RACES OF INDIA 
Memoirs on the History, Folk-lore, and Distribution of 
the Races of the N.W. Provinces of India. By the 
late Sir Henry M. Elliot. Edited by J.Beames. (2 
vols, Triibner and Co.) 
a= above work dates from the time of the old East 
India Company, bearing ample witness anew to that 
glorious fertility of genius produced in the full flow of an 
activity directed seemingly to the development of a purely 
mercantile policy of the most practical kind—the utilising 
of a distant continent for the enrichment of a hand- 
ful of merchants sitting at home at their ease. Such, at 
least, was the repute enjoyed by the Honourable Court of 
Directors in their day, and it required no less a change 
than the transfer of power to as methodical a form of 
government as that which rules India nowadays to make 
us see matters in their true light, and bless the memory of 
John Company. This remark is made, of course, from a 
scientific point of view, for in every other respect, doubtless, 
India has at large been the gainer. The Company had 
served its term, and had to give way to a more central 
power in the interest of the empire generally. One 
cannot help contrasting, however, the times that are 
gone by, when upon the horizon shone such stars 
of first magnitude in science and literature as Sir 
Charles Wilkins, Sir William Jones, Gilchrist, Lumsden, 
Colebrooke, Wilson, Ballantyne, Charles Philip Brown, 
Roer, Sprenger, with the days that be, when examination 
tests of the severest kind are in the ascendant, but followed, 
alas ! by no apparent results as far as growth of scientific 
knowledge is concerned, whatever advantage the service 
generally may be found to derive from them. Men there 
* MSS. of Leonardo da Vinci, vol. N, fos. 11 and 71. 
t Principles of Geology, 1oth ed. vol. 1. p. 31. 
