received my proofs. 
NovEMBER 26, 1396] 
WA PURE 
reached finality and gives them totally false ideas as to what we 
know. It is so easy to make use of all that is good in the new 
work by substituting a neutral phrase, such as coefficient of 
activity, for coefficient of dissociation—for all that we have really 
done is to recognise that certain compounds exercise a superior 
degree of activity, and to measure the relative degree of activity 
of these. To substitute for common-sense expressions which all 
understand—and even to promulgate at County Council expense 
—a set of shibboleths which commit us to a definite hypothetical 
interpretation of the facts is unnecessary, undesirable, and un- 
scientific. Such metaphysical speculation is obviously doing the 
deepest injury to the cause of exact science. 
Henry E. ARMSTRONG. 
On the Publication of Original Work. 
Mucu has been written and said as to the facilities for the 
publication of original researches in this country. It is now 
becoming quite a regular custom for English comparative 
anatomists to publish their work in a foreign journal. Not 
only the morphologist, but also the systematist has found 
this necessary. One is naturally led to inquire why—with 
so many learned and wealthy societies in our midst—pub- 
lication cannot be effected so as to give the author the necessary 
printing and illustration in a style comparable with that of 
continental journals, and with a minimum amount of delay? 
In this country the only sources of publication for mono- 
graphs on zoological subjects are the PAz/. Trans. of the Royal 
Society, the Zyavs. Zool., and the Zrans. Lin., and of these 
it would naturally be supposed that the Zvans. Zool. is pre- 
eminently the place for such publications. But it will scarcely 
be credited that a wealthy Society like this, for some unknown 
reason, should allow in some cases as long as two-and-a-half 
years to elapse before publication of material received. Thus I 
find, on referring to volumes of the 7yavs., a paper received 
November 1, 1892, read December 20, 1892, was published in 
February 1895. Another, received December 5, 1892, read 
February 14, 1893, was published October 1895. Still another, 
received October 14, 1893, read November 7, 1893, was not 
printed till April 1896! These are examples chosen at random. 
There seems no obvious reason why any or all of these 
should not have been published within six months from the date 
of reception. A fourth instance, which I here wish to narrate, 
will, I trust, serve the purpose of showing zoologists the need 
of some more speedy means of publication. 
In the winter of 1894-95, I completed a piece of work on the 
suprarenal capsules in fishes, and was advised to offer it to 
the Zoological Society for publication. The paper was received, 
in the first instance, on June 6, and I hoped it would have been 
taken as read at a meeting of the Society held in that month. 
It was, however, not read till November 19, when Prof. Howes | 
was good enough to undertake it for me. It was ordered for 
publication in the Zyans., and now (November 14, 1896), 
nearly twelve months from the date of reading, I have not yet 
Surely such extraordinary delay as this 
ought not to be necessary. 
During such a long period I have found it necessary to keep 
pace with much literature bearing upon the subject ; but more 
than this, I have just suffered the chagrin of seeing a paper em- 
bodying a large slice of my results published by an Italian 
journal. 
Perhaps some others will be found to agree with me that 
some means ought to be found of getting earlier publication in 
comparative anatomy and allied subjects. In the minds of 
many, I feel sure, there can be little doubt that the Zoological 
Society should undertake such work. 
I do not wish to make out that I have been treated excep- 
tionally, or in any way unjustly. My experience has been no 
worse than that of many others. The officers of the Zoological 
Society have treated me with every courtesy, and have even 
allowed me to publish an abstract of my paper elsewhere. But, 
mevertheless, I fail to see why the work could not have been 
published within six months from the time of reception. 
SWALE VINCENT. 
Mason College, Birmingham, November 14. 
Cultivation of Woad. 
As supplementary to the article on the cultivation of woad, 
by Messrs. Darwin and Meldola, in Narure for November 12; 
it may further be stated that this plant has been grown besides 
5 
TO. Tae, Orn cS | 
at Parson Drove, at Boston, Wyberton, and Algarkirk, in the 
Lincolnshire Fenland, for a very long period. An account of its 
cultivation, with details of the process and preparing it for use, 
will be found in Arthur Young’s ‘“ Agricultural Survey of 
Lincolnshire,” published at the end of the last century. A more 
modern account will be found in ‘‘ The History of the Fens of 
South Lincolnshire,” recently published. This plant is not 
cultivated in any other part of England than the Fenland, and 
the total area grown altogether yearly does not, as a rule, exceed 
fifty acres. It requires very good land for its cultivation, and 
much rich old pasture land has been broken up for the purpose, 
for which as much as 10/7. an acre has been paid for rent, and 
150/. to 200/. for purchase of the freehold. | The price obtained 
for woad was formerly about 252. a ton, but it has declined in 
recent times to 9/ or 10/7 The woad, when prepared for 
market, is not used for dyeing, but is mixed by woollen dyers 
with indigo to excite fermentation and fix the colour. 
Boston. W. H. WHEELER. 
WITH reference to your article on ‘* An English Woad Mill,” 
may I mention that Billingsley, in his book, published in 1798, 
on ‘* Agriculture in the County of Somerset,” mentions woad as 
an important article of cultivation, raised principally in the 
neighbourhood of Keynsham, near Bath. The mode of prepara- 
tion, described by Billingsley as in use one hundred years ago, 
closely resembles the description given in NATURE as in use at 
the present day. He adds that the crop is a profitable one ;_so 
lucrative, indeed, that few farmers who can raise it, ever dis- 
continue the practice. He also mentions that it was cultivated 
by one Harvey, more generally known as the ‘‘ Woad-man,” at 
a farm near Mells. The cultivation of woad does not appear, 
therefore, to have been so very rare in the last century ; but 
whether it is still cultivated in Somersetshire, I am unable to 
say. Rosa M. BARRETT. 
Kingstown, Dublin, November 14. 
‘* X-rays with a Wimshurst Machine.” 
THeRe is an error, for which I am responsible, in my letter of 
July 24 (p. 31). The words kathode and anode should be inter- 
changed in one sentence, which should then read thus :—‘‘ The 
same reasoning would indicate that it would be well to make 
the anode convex towards the £athode, and fairly small. . . .” 
Eton, November 13. T. C. PORTER. 
FLYING BULLETS. 
@ets recently M. Tissandier, editor of La Nature, 
Z received from Prof. Mach, formerly Professor of 
Physics at Prague, now Professor of the history and 
theory of inductive science at Vienna, a letter contain- 
ing a photograph of a bullet in motion (Fig. 1). The 
photograph was taken by Prof. Mach’s son, and shows 
most clearly the waves of air caused by the bullet’s 
passage through the atmosphere. 
M. Tissandier, wishing for an explanation of the 
experiment and description of the apparatus, wrote to 
Prof. Mach, and received the accompanying diagram 
(Fig. 2), with the following short account. “My son 
took the photographs of the bullet by using a spherical 
silvered-glass mirror. MM is the mirror, P the bullet, 
~ the screen, B the photographic apparatus, S$ the 
spark. The bullet causes a sonorous wave, by which 
the Leyden jar is mechanically discharged, and produces 
the spark s.” ; 
It may be added that the description of his first 
apparatus appeared in La Wa/ure of 1888. 
Our readers are also familiar with the photographs of 
flying bullets which were exhibited at the soirée of the 
Royal Society in May 1892. These were results of 
experiments made by Mr. Vernon Boys, obtained by a 
modification of an old method. One slide showed the 
small pieces of paper scattered by the bullet passing 
through a sheet, and these were carried on in the same 
direction as the bullet itself; whereas in the case of a 
magazine rifle bullet going through a sheet of glass, the 
shattered pieces of glass appeared to travel in an opposite 
