196 
mixed with putty, without injury. They thrive on the 
linseed oil used in the manufacture of this most unsavoury 
side-dish and the whitening which forms the other ingre- 
dient of “paté de putty” seems to neutralise the evil 
effects of the lead. The bearings of these facts are im- 
portant from a sanitary point of view, as Prof. Storer 
shows that the effects of mice eating away the packing of 
valves, of drains, and closets is an immediate frustration 
of the best efforts of plumbers and sanitary engineers to 
keep human habitations free from sewer gas. Not content 
with mice, the Professor tried similar experiments upon 
rats, when it was found that “rats when kept upon a rather 
short allowance of oats, ate putty freely. Finally “the 
surviving rat was fed with ‘ plain putty’ for a day or two, 
after which he received and ate (poor wretch) each day 
for two days a ball of putty made with a mixture of equal 
parts of slaked lime and whiting. He was next givena 
ball of putty made from a mixture of one part of oxide of 
zinc and three parts of whiting, together with 2} grammes 
of oats, and although he ate very little of the ball he died 
soon afterwards.” The chief result of these experiments 
appears to be the injury rats and mice may do to houses 
and the curious protecting effect of whitening as an anti- 
dote to such active poisons as red and white lead and 
carbonate of baryta. Experiments upon the germination 
of weed seeds and a special instance of the resistance of 
clover seeds to water form two very interesting notes 
bearing directly upon well-known phenomena often 
ascribed by the ignorant to spontaneity of growth. The 
extraordinary irregularity of periods necessary for the 
germination of certain weed seeds is very clearly shown. 
“ Of 400 seeds of shepherd’s purse (Cafsella bursa pastoris) 
three germinated on the fifth day and three on the seventh 
day, then none until the 145th day, when four germinated. 
Seven seeds germinated on the 1173rd day, or after an 
interval of about three years and eat months—in all 18% 
per cent. to that date.” Many similar cases are cited. 
Another article is upon “cherry stones eaten by domestic 
pigeons,” which appears unpromising, but is rendered 
interesting by this versatile observer. Prof. Storer is 
evidently a man who is not likely to allow any natural 
phenomenon to pass unnoticed. 
JOHN WRIGHTSON 
LETTERS TO THE EDITOR 
[ Zhe Editor does not hold himself responsible for opinions expressed 
by his correspondents. Neither can he undertake to return, 
or to correspond with the writers of, rejected manuscripts. 
No notice ts taken of anonymous communications. 
[The Editor urgently requests correspondents to keep their letters 
as short as possible. The pressure on his space is so great 
that it is impossible otherwise to insure the appearance even 
of communications containing interesting and novel facts.) 
Clifford’s Common Sense of the Exact Sciences 
Ir does not seem to me necessary to reply to the charges made 
against Clifford by Prof. Tait in your issue of June 11—charges 
which, when freed from ‘‘ mystery and insinuation,” amount to 
accusations of plagiarism and inaccuracy—for Clifford’s reputa- 
tion is unlikely to be in any way affected by what Prof. Tait 
may write. But I do feel it necessary to make a remark on the 
last paragraph of his review. He therein accuses me of 
‘‘mystery and insinuation,” weapons which should not be 
employed in connection with Clifford’s name. 
do me the scant justice of publishing the footnote on which he 
passes these strictures. That footnote runs as follows :— 
‘* A still more serious delay seems likely to attend the publi- 
NA LORE 
He does not | 
-tions “of the author. 
; escaped correction.” 
[Fuly 2, 1885 
(2) That this manuscript, unlike that of the ‘‘ exact sciences,” 
had not at that time found a publisher, and therefore was more 
likely to be seriously delayed. 
(3) That the mathematical world had been so far forgetful of 
its own interests as to raise no demand for its publication. 
My note was written with the express purpose of recalling the 
attention of those who valued Clifford’s work to the existence of 
this manuscript, in order that a general demand for its publica- 
tion might produce a publisher. Those who find ‘ mystery or 
insinuation” in this, or in whom this can ‘strike a jarring 
chord,” must be singularly constituted individuals. The note 
had on the face of it an obvious purpose; that purpose, I am 
happy to know, it has to some extent helped to accomplish. 
University College, June 12 KOR. 
On ‘‘K, P.’s” note, which has been communicated to me by 
the courtesy of the editor, I desire to make one or two remarks. 
In writing my notice of Clifford’s book I endeavoured to state 
clearly the impression which its perusal had produced in my own 
mind, and to say a few fitting words as to the special qualifica- 
I must have sadly failed in this endeavour 
if in what I have written there can be found either mystery or 
insinuation, still more so if there can be found ‘accusations of 
plagiarism and inaccuracy.” But of course even an Act of Parlia- 
ment has to be construed after the letter, the declared intention 
of its framers notwithstanding. On reperusing my notice, how- 
ever, I still think that it expresses what I meant to say, and that 
it cannot bear the construction put on it by ‘* K. P.” 
The remarks I made on the foot-note to the Preface accurately 
described the impression which it produced on me, and which I 
am sure it is likely to produce on the majority of thoughtful 
readers. So strongly did I feel this impression that, when I 
finally returned my notice for press, ‘I specially requested the 
editor to try to obtain for me an elucidation of the mys'cry. 
This has been—in part at least—supplied by Mr. Tucker’s note. 
Whether ‘‘R.,” who writes in NATURE of this week, be 
really a ‘‘ (so-called) metaphysician” or no, he certainly ex- 
presses himself in the language of that school; for he mildly 
characterises as ‘‘not sufficiently guarded” the statement that a 
figure, obtained in a certain way, will be a cube :—whereas it 
obviously may be any rectangular parallelopiped whose edges are 
commensurable. But I did not blame Clifford for having made 
this statement; I merely said that it ‘‘ought not to have 
Perhaps even that expression is too strong. 
I have lately learned by experience that over-zeal on the part of 
a press-reader may sometimes render abortive the most sedulous 
care on the part of an author. Over and over again I have had 
proof-sheets, marked ‘‘ gress,” returned to me with a learned 
query at the phrase ‘‘ feet per second, per second” ; and in one 
or two instances the supposed blunder has been rectified after all 
in spite of me. P. G. Tair 
June 26 
Recurrence of Markings on Jupiter 
In connection with my remarks on this subject (NATURE, 
Xxxil., p. 31), and the suggestive coincidences which appear 
anand certain drawings obtained in about the years 1857 and 
1859, “1870 and 1872, and 1885, as to large elliptical markings 
in the southern hemisphere of Jupiter, I would further add that 
in about 1843 a remarkably large spot was visible, which may 
possibly be connected with the phenomena of more recent oc- 
currence. Prof. Piazzi Smyth mentions in the Observatory, 
vol. lii., p. 450, that, in consulting some old observations pre- 
served in the note-books of the Rev. H. C. Key, he found ‘‘a 
view of Jupiter, with not only the dark belts admirably drawn, 
but between them, in stronger black colour, a long oval spot. 
This spot, too, was so precisely the shape and size of the red 
spot which has of late been attracting the surprised attention of 
observers, that I could not but jump to the almost self-evident 
| conclusion of their both referring to the same body, appearance, 
cation of the second part (Aimetic) of Clifford’s ‘Elements of | 
Dynamic,’ the manuscript of which was left in a completed | 
state. I venture to think the delay a calamity to the mathe- 
matical world.” 
When I wrote the footnote, I knew— 
(1) That the manuscript was in existence, a fact with which 
any one who had examined the bibliography attached to the 
mathematical works must have been acquainted. 
or phenomenon.” The drawing alluded to was made on June 4, 
1843, and Mr. Key described it as a “horizontal black spot in 
the light space between the two principal belts.” In Chambers’ 
“Descriptive Astronomy” (2nd ed., p. 107) it is stated, ‘‘In 
1843 a very large black spot was observed by Mr. Dawes,” and 
this object is doubtless identical with that figured by Mr. Key. 
It will be important to compare the observations and to learn 
whether these spots were situated in approximately the same 
latitude as the red spot of our own time. 
