Nov. 25, 1869] 
NATURE 
103 
*I have taken advantage of the late meeting of the 
British Association, at Exeter, to bring the subject 
before meteorologists. It appears that the general term 
meteorology embraces two entirely distinct subjects, one of 
these having reference to physiology, while the other 
forms a branch of physical research. 
The object of the one is to study the connexion between 
atmospheric conditions, and the health of such organisms 
(animal and vegetable) as are subjected to these con- 
ditions ; while the other or physical question is par- 
ticularly concerned with the movements of the earth’s 
atmosphere, and with the causes thereof. 
On both of these important branches we are in almost 
entire ignorance. With respect to the first, the amount 
of vapour present in the air is without doubt a very 
important element of climate, inasmuch as this affects 
in a marked manner the skin of the human body, and 
the leaves of plants; but I am not aware that it has 
yet been determined by the joint action of naturalists 
and meteorologists what is the precise physical function 
expressing proportionally the effect of moisture upon 
animal and vegetable life. Is it simply relative humidity ? 
or does not a given relative humidity at a high tempera- 
ture have a different effect from that which it has when 
the temperature is low? There is, in fact, an absence of 
information as to the precise physical formula which is 
wished by physiologists, as expressing the effect of moisture 
upon organic life. 
If we come in the next place to consider the physical 
branch of meteorology, or that which regards the motions 
of the earth’s atmosphere, this is almost as far behind. 
The explanation of the trades and anti-trades is the one 
great gencralisation which we have accomplished. Certain 
laws regarding cyclonic storms have lately been discovered $ 
but to this day we are in ignorance of that exact motion 
of air which constitutes a cyclone, some holding that the 
motion is entirely rotatory, while others maintain that there 
is a considerable indraught of air from the circumference 
to the centre. Again, there is no fact better established 
than the diurnal movements of the barometer ; but what 
is the motion of air,or its constituents implied by them is 
still a point open to dispute. Now, these are both matters 
of fact, and there must be some reason why we know so 
little about them. Nothing, of course, could be known 
until the instrumental difficulties of the problem had been 
surmounted, and a suitable anemometer constructed ; but 
now, we have good instruments, and have begun’ to make 
good observations. What, then, is the remaining draw- 
back? I believe it is to be found in the fact that while 
instrumental appliances and observations have progressed, 
methods of reduction, which naturally lag behind observa- 
tions, have not yet progressed, but are only just beginning 
tomove. Those hitherto in use combine the physiological 
with the physical element,—they are a cross between the 
two, and are subject, I venture to say, as all such crosses 
are, to the general law of barrenness. Still not much 
time has been lost, for in the dark ages of few and bad 
observations it would have been useless to divide the 
meteorological field: meteorology, then, might be likened 
~to one of those organisms of very low development that had 
just begun to exhibit the slightest possible tendency to 
\ split into two ; the application of the knife would then have 
, been premature ; but now it may be used with advantage, 
and the one half allowed to rush into the arms of physio- 
logy, while the other seeks the embrace of physical 
research. In plain language, if we want to obtain physio- 
logical results we must reduce our observations with 
especial reference to physiology, while if physical results be 
desired, they must be reduced with especial reference to 
physical laws. 
I must, however, reserve for another article a de- 
scription of a method of reduction having this latter 
object in view. BALFOUR STEWART 
PREHISTORIC TIMES 
Prehistoric Times, as illustrated by Ancient Remains, and 
the Manners and Customs of Modern Savages. By 
Sir John Lubbock, Bart., F.R.S., &c. Second Edition, 
(London, 1869: Williams and Norgate.) 
WE may be pardoned for not being cosmopolite 
enough to judge books without any regard to 
their nationality. Too often, though Englishman may 
have contributed much to some important subject, no 
systematic English treatise sums up the evidence, so that 
our students have to depend too much on foreign books of 
reference. On the present subject of prehistoric archee- 
ology, however, it is satisfactory that we have, in Sir John 
Lubbock’s work, not only a good book of reference, but 
the best. Its well-known plan and argument need not 
be re-stated here, but it has to be pointed out that the 
present edition contains much important new matter, 
especially in the chapters relating to the Stone Age, 
Megalithic monuments, Cave-men, and the condition or 
modern savages. ; 
It is a marked character of the recent researches in 
prehistoric archeology, and it is one of the reasons which 
justify the reception of the subject as a department of 
positive science, that the facts disclosed lend themselves 
to generalisations of a thoroughly scientific character; and 
that, moreover, when the generalisations are once made, 
new facts drop in and find their places ready. Various 
subjects discussed in the present work illustrate this: 
take, for instance, the stone-implement question. The 
finding of flakes, scrapers, spear-heads, &c. in different 
parts of the world, justified a general surmise that the 
Stone Age had once prevailed in all inhabited districts. 
A few years ago, however, there were regions whence 
stone implements seemed hardly forthcoming. India 
appeared to have none, but when properly looked for they 
proved abundant, as witness Mr. Bruce Foote’s paper in 
the Transactions of the Norwich Congress of 1868. Africa 
also seemed almost outside the Stone Age world; but now 
the finding of stone implements in South Africa, and even 
legends of their use, give the primal Stone Age possessions 
there as elsewhere. No sooner, too, were the rude imple- 
ments of the Drift type thoroughly recognised in the 
valley of the Somme, than it came into notice that such 
had long before been collected in England without know- 
ledge of their special importance ; and now Spain and 
India, and other districts, furnish specimens which come 
under the same class. So it was with the art of fire- 
making by friction of pieces of wood. Over most of the 
world, savage or civilised, the traces of its early prevalence 
were sufficient to justify its being generalised on as one of 
man’s primitive arts. But there were some exceptional 
cases, as in Tasmania, where the natives were said to 
