362 
NATURE 
b i 
* 
[A ugust a8 I 885 
due to a constantly increasing attraction exerted by the 
sun upon a constantly diminishing mass. 
Of course, if this novel theory can stand the test of a 
full comparison with facts, it will have established its 
claim to become part of science. But it is hard to take 
leave of the simple old ideal comet :—the swarm of cos- 
mical brickbats :—something imposing because formid- 
able ; and to see it replaced by what is, in comparison, a 
mere phantom, owing its singular appearance to the com- 
plexity of the physical properties it possesses and the 
recondite transformations perpetually taking place in its 
interior. The old idea of a comet’s constitution was not 
only formidable, but was capable of explaining so much, 
and of effecting this by means so simple and so natural, 
that one almost felt it deserved to be well-founded! The 
new idea makes it resemble the huge but barely palpable 
’Efreet of the Avabiéan Nights, who could condense him- 
self so as to enter the bottle of brass with the seal of 
Suleymdn the son of Ddood! 
It is much to be desired that more detail had been 
bestowed on the nebule. As nothing is said about the 
origin of their incandescence, we must take for granted 
that it is supposed to be due to gravitation. A few rough 
numerical assumptions as to dimensions, total mass, &c., 
and the consequent thermal condition at each stage of 
condensation, would have formed materials for a most 
instructive explanatory note. 
The last lecture deals with solar protuberances; the 
(so-called) Doppler’s principle, and the results of its appli- 
cation; and, finally, with the body of the sun. The 
explanation given of the peculiar and rapidly changing 
structure of the sun’s apparent disc, which is so well 
shown in Janssen’s splendid photographs, reminds us of 
a suggestion made several years ago :—viz. that a suc- 
cession of instantaneous photographs should be taken, at 
short intervals, of so homely an object as a basin of very 
hot “beef-tea,” which has been agitated so as to bring the 
flocculent matter fully into suspension, and is then left to 
itself as nearly as possible free from rotation. 
The passages in the present volume which, taken by 
themselves, would indicate the ulterior object of the lec- 
tures are not numerous, and nowhere bear the appearance 
of having been inserted for a purpose, so naturally do 
they arise as comments on what has just been discussed. 
We wish the Author as high a measure of success in 
his final effort, the most arduous of the three, as he has 
already attained in the others :—it would be preposterous 
to wish him a higher. The series will then form an ex- 
ceedingly valuable contribution to a class of literature in 
which marked success is scarcely attained once per 
generation, and is justly valued in proportion to its 
rarity. PaG. Garr 
AGRICULTURAL EXPERIMENTS 
Review of Agricultural Experiments by the Right Hon. 
Sir Thomas Dyke Acland. (London: Clowes and Co., 
1885.) 
HIS purports to be a critical review with suggestions, 
and is actually an attack upon the objects, aims, 
and results of the Sussex Association for the Improve- 
ment of Agriculture. The writer brings a long experience 
and a good business faculty to bear upon the working of 
a scientific organisation, and with some success so far as 
these instruments may be used as tests of the value of a 
delicate task requiring very special knowledge. The atti- 
tude of mind of the reviewer of these experimental results 
is one of scepticism. This he does not scruple to express 
in such terms as “we all felt rather sceptical,” and “we 
suspected,” and “I have made in all four visits to Sussex 
to endeavour to get at the truth.” Again, “ Well, thought - 
I, this must be a queer kind of farming, perhaps I shall 
enlarge my experience. I think I have made out since 
that the local experience, however practical, may be the 
better of a little expansion.” With such introductory 
remarks we can hardly look for the cold judicial criticism 
that commands attention and carries conviction. 
The inquiries of the Sussex Association have been 
directed to very practical questions, viz. :— 
What do roots (turnips, mangolds, &c.) require? 
What do wheat and other cereals require ? 
What does grass or pasture require ? 
These objects Sir Thomas Acland appears to view in 
two opposite and irreconcilable ways. First, he seems to 
doubt the possibility of these questions being solved by 
experimental processes. Secondly, he appears to con- 
sider that they have all been answered long since. He 
thus discounts the value of the Sussex results from two 
points of view, each of which is destructive of the 
other. Itis true that the leading facts constituting the 
answers to the above important questions have now been 
firmly established for many years, and that these answers 
were known almost a generation ago to such leading men 
as the late Philip Pusey, and all more recent scientific 
agriculturists. The value of such stations as that known 
as the Sussex Association consists in its power of im- 
pressing and verifying such facts, as well as in discovering 
new ones, and we think, under Mr. Jamieson’s able guid- 
ance both of these objects are being accomplished. 
Among new ideas promulgated by the Sussex Association 
is that which is paragraphed by Sir Thomas Acland under 
the heading, ‘ Battle of the Phosphates.” Mr. Jamieson’s 
contributions upon this important subject are passed over 
with something akin to contempt, and yet (however dis- 
tasteful his conclusions may be to manufacturers of 
“superphosphates”) his results remain unrefuted, and 
the most recent experiments at Woburn point, on the 
whole, to similar conclusions. The establishment of the 
value of “insoluble” phosphatic minerals reduced toa 
fine state of division is due in a great measure to Mr. 
Jamieson, and he has incurred no little unfriendly critic-. 
ism on account of this new doctrine, which touches the 
pockets of certain strong interests. This is altogether 
the leading truth brought out and fought for by Mr. 
Jamieson, and yet it is dismissed by Sir Thomas Dyke 
Acland in a manner which appears to the present writer 
as simple superciliousness. 
One could scarcely expect to read sixty-four pages of 
printed matter from the pen of Sir Thomas Dyke Acland 
without finding grain as well as “chaff.” We therefore 
wish to set forth the useful criticisms which the Sussex 
Association would do well to notice. First, then, there is 
the fallacious method adopted in endeavouring to trans- 
late field results into money values. Not content with — 
leaving the number of bushels per plot and pounds of straw 
increase to the judgment of the reader, an effort has been 
