April 13, 1882] 
NATURE 
551 
On the whole, then, while we have not been able to 
find any statement which is certainly and distinctly 
wrong, we find a very great deal which is not only 
certainly and distinctly right but which is also exactly 
that concerning which a real student desires, but has 
hitherto been unable to obtain, information; and the 
whole is well and clearly written. We cannot therefore 
too strongly recommend teachers to adopt it at once as 
their text-book. Ona 
OUR BOOK SHELF 
The Tea Industry in India; a Review of Finance and 
Labour, and a Guide for Capitalists and Assistants. 
By Samuel Baildon, author of ‘Tea in Assam,” &c, 
(London: W. H. Allen and Co., 1882.) 
THE history of the discovery and introduction of what is 
generally known as Chinese tea, though often to!d, has a 
special interest to a very large proportion of the inha- 
bitants of the civilised world. In every country, indeed, 
on the face of the globe, the people use some beverage 
which they know as tea, and which is prepared in a 
similar way to that in use amongst ourselves, namely, by 
infusion, and often, though made from the foliage of 
indigenous plants, having the same chemical properties as 
truetea. Considering the enormous money value the culti- 
vation of the tea plant represents not only in this country, 
but in China and also in India, where it is continually 
extending, it follows that works on this special industry 
would meet with a wide circulation amongst planters, and 
managers and directors of tea companies, notwithstanding 
that books and papers on the subject are by no means 
scarce. 
The work before us is one which, though containing a 
a good deal of information on the practical working and 
financial aspects of tea planting is, moreover, written in 
a style that will be generally acceptable, especially among 
“young planters, who have their way to make in the plant- 
ing world, and who want the dry details or drudgery of a 
planter’s routine of toil stated in a clear and at the same 
time easy manner. 
We will not follow Mr. Baildon through all his 
chapters. A glance at the introduction will prove that 
his reason for writing the book has been to show that 
India is ‘Ae country from whence we get the finest teas, 
and that it is also the country where we may look in future 
years for the bulk of our supply, holding out inducements, 
as many districts do, for the investment of capital and the 
application of bodily health and talent. In Chapter II., 
on ‘‘India the Home of the Tea Plant,” quotations are 
largely made from the published werks of well-known 
botanical authorities, to show that though cultivated from 
such a remote period in China that the plant is truly 
indigenous to India. The legends connected with the 
origin or discovery of the tea plant in China are told, one 
of which refers its discovery to the year of grace 510. 
The author points out that these legends do not prove 
that tea was discovered in a wild state in China. “The 
earliest mention,” he says, “tells of people using it, and 
it may be inferred therefrom that they cultivated it. 
Precise and accurate information is obtainable as to the 
actual discovery of tea in Assam, away from habitations 
and in dense jungles far from ‘cultivated grounds.’ But 
similar information is not obtainable in connection with 
the first days of tea amongst the Chinese.” 
Referring to the altered character of certain districts in 
India now under tea cultivation, Mr. Baildon says, “ Where 
once jungle and its deadly miasma concealed the riches 
and importance of the province, hundreds of thousands 
of acres of open land are now to be seen planted with tea. 
Compared with past times Assam is no longer a howling 
wilderness, and the change from hundreds of miles of 
waste into cultivated land has altered almost everything.” 
In proof of the superiority of Indian over China teas, 
the author advances many arguments and anecdotes 
of a powerful nature, which, however, may be summed up 
in the simple statement “that it is systematically used to 
fortify tea from China,’’ and that there is only one case 
on record of anything approaching adulteration of Indian 
tea. It is stated that ‘‘every pound offered for sale in 
England can be guaranteed as absolutely pure,” and this 
is its reputation with the trade. Mr. Baildon’s statements 
on this head are, we believe, an honest record of facts, 
for it is well known that Indian teas are largely used in 
this country for mixing with inferior China teas. This 
system is well known as “blending,” and is stated to be 
resorted to because the public taste has not yet become 
educated to the flavour of Indian teas alone. The 
English tea drinker, however, is rapidly assuming a taste 
for the Indian produce, and the demand for Indian tea is 
already very great. 
On the question as to the kind of men likely to succeed 
as tea planters in India, Mr. Baildon has a great deal to 
say, and is very outspoken in what he does say. His 
estimate of a successful planter is evidently drawn from a 
thoroughly practical experience, and will no doubt serve to 
encourage some, as it will to discourage others. 
The book has been carefully revised, and is unusually 
free from blunders, the author wisely omitting to go into 
the botanical character of the tea plants any more than a 
reference to the names under which the forms have been 
described. 
A Treatise on the Theory of Determinants; with 
Graduated Sets of Exercises for Use in Colleges and 
Schools. By T. Muir, M.A., F.R.S.E. (London: 
Macmillan, 1882.) 
THERE has been a tendency of late among some of our 
mathematical writers to specialise their labours; thus, 
Dr. C. Taylor has confined his work chiefly, if not mainly, 
to the geometry of conics; and our present author, to the 
subject of determinants. This is, we think, a good 
practice. Mr. Muir is no novice, and has done good 
work in this field, much of which is original. We have 
long desiderated some such work as this. Mr. Scott's is 
very able, but we cannot but think it is hard for junior 
students. Mr. Muir, we are disposed to believe, has made 
the introduction to the subject easier for this class, at the 
same time that he brings before the reader all that could 
be expected in a text-book. The work before us consists of 
three chapters, the two first of which do not err on the 
side of brevity; but this fulness serves a purpose, viz. 
“‘that the reader may become thoroughly familiarised 
with the definition,” which, by the way, is too long for 
us to reproduce here. Though the enunciation is long, 
the idea is easily grasped, and when taken in connection. 
with the illustrations, is not likely to give much trouble 
to the student to master it. These chapters, as indeed 
the remaining one also, are copiously illustrated by 
graduated exercises. The third chapter is much more 
condensed in style, and treats of determinants of special 
form, viz. continuants, alternants, symmetric determinants, 
Skew determinants, and Pfaffians, compound determinants, 
and determinants whose elements are differential coeffi- 
cients of a set of functions, to wit Jacobians, Hessians, and 
Wronskians. 
In a final chapter is given an interesting historical and 
Bibliographical Survey, from which the reader learns that 
contributions have been made to the subject from the 
publication of the germinal idea (long unfruitful) by Leib- 
nitz in 1693, down to this present work. We may refer 
for further information to the chronological “List of 
Writings on Determinants” (1693-1880), published by 
Mr. Muir in the Quarterly Journal of Mathematics for 
October, 1881. This, the completest list we have seen, 
was to have formed part of the present work. Though 
we have carefully read the book through, with the excep- 
tion of the exercises, we have detected but three or four 
