JANUARY 3, 1907 | 
NATURE 
219 
flammable vapour present in the air long before the 
mixture becomes itself inflammable. 
In these days, when petroleum spirit is so largely 
stored and used for motor purposes, and when so 
many steamers are engaged in the oil trade, tests 
capable of revealing any dangerous leakage of vapour 
are of the greatest importance, and the “‘ flame cap ”’ 
offers a certain method of detection. : 
The tenth section of the work deals with the uses 
of petroleum and its products, and commences with a 
full description of the various types of oil lamp fitted 
for the consumption of mineral oils, and a full dis- 
cussion of the dangers due to them. A careful study 
of this portion of the section would do much to 
disabuse the minds of that portion of the British 
public which has been lately clamouring for an in- 
crease in the flash point, with the idea that this 
would minimise the danger of the oil lamp, and 
especially may the following paragraph be recom- 
mended to its notice :— 
“Experiments have demonstrated that the burning 
of an oil of comparatively high flashing point is more 
likely to cause heating of the lamp than the use of 
an oil of comparatively low flashing point, in conse- 
quence of the higher temperature developed by the 
former, and of the greater difficulty with which some 
oils of that description are conveyed to the flame by 
the wick. It therefore follows that safety in the use 
of mineral oil lamps is not to be secured simply by 
the employment of oils of comparatively high flashing 
point (or low volatility), and that the use of such oils 
may even in certain cases give rise to dangers, which 
are small, if not entirely absent, with oils of compara- 
tively low flashing point.”’ 
The use of oil in spray lamps, the so-called “ air 
gas,’’ the enrichment of coal gas by carburetting, 
carburetted water gas, oil gas, and natural gas are 
here all described and discussed, whilst the use of 
liquid fuel leads to a full description of the various 
methods which have been employed, but unfortunately 
the author’s position as leading adviser on petroleum 
to the Admiralty has prevented his giving any ex- 
tended notice of the advances which have made the 
liquid fuel installations of the British Navy the finest 
and most successful in the world. The section closes 
with a short account of the principles upon which 
petroleum engines are constructed, but, as the author 
points out, the motor-car industry and consequent 
development of petrol engines has assumed such vast 
proportions that it now possesses a voluminous litera- 
ture of its own, which has far exceeded the scope of 
the present work. 
A section on the statutory, municipal, and other 
regulations affecting petroleum and its products brings 
the work to a close, whilst a voluminous appendix 
and excellent index add to its value. So full are the 
references to all original memoirs noticed in the book 
that a bibliography of the subject at first seemed 
hardly necessary, but Messrs. W. H. and L. V. Dalton 
have compiled one which will rejoice the heart of 
every student of the subject. 
The petroleum industry is indeed fortunate in pos- 
sessing such a work of reference, and Sir Boverton 
Redwood has done the world a great service in 
providing it. 
NO. 1940, VOL. 75 | 
RECENT ADVANCES IN PHYSIOLOGY. 
Mercers’ Company Lectures on Recent Advances in the 
Physiology of Digestion. By Prof. Ernest H. 
Starling, F.R.S. Pp. x+156. (London: Archibald 
Constable and Co., Ltd., 1906.) Price 6s. net. 
AS time advances it becomes ever clearer to many of 
+ those whose business it is to consider the manner 
in which university teaching should be carried on that 
the usual systematic course of lectures on the whole 
range of any of the larger divisions of human know- 
ledge is an anachronism surviving from the time when 
there were no good text-books, and knowledge had to 
be conveyed directly from lecturer to student. 
In all the medical schools of the country at the pre- 
sent day, professors or lecturers hold appointments 
which entail upon them the duties of lecturing over 
the whole of such subjects as systematic medicine, sys- 
tematic surgery, physiology, or pathology and bac- 
teriology. It is to be hoped that within the progress 
of a single generation such appointments may have 
ceased to exist, and that the student of the future may 
be able to give to the laboratory or the clinique that 
large section of his time which is at present misspent 
in the lecture-room. What applies to the long lecture 
course, too often extending over two whole winter 
sessions, applies with equal or greater force to the 
text-book written upon the whole range of a large 
subject. : 
The present volume forms a delightful and refresh- 
ing contrast to any such wearisome compilation; it 
consists of a short course of ten lectures given by a 
master worker to his students, chiefly upon the work 
done in his own laboratory by himself and his col- 
leagues. This appears to the writer to be the ideal 
of what a lecture course should be, namely, some- 
thing stimulating to enthusiasm and capable of 
sending the listener into the laboratory with the 
desire to work and learn more—a contrast in every 
sense to the mechanical lecture, which must 
wade monotonously through everything, and, gramo- 
phone like, repeat from year to year the phrases 
and the stereotyped long-dead thoughts of text- 
books devised on the same mechanical system. It 
is to be hoped that such special courses of lectures 
and specially written text-books, given and written by 
those in living touch with the subject in hand, may 
soon replace the universal lecturer and universal text- 
book. 
Naturally, in order to present in intelligible form 
the work of any one laboratory, it is necessary to place 
it in its appropriate setting to the work of others which 
has preceded it and led up to it, and to give for com- 
pleteness contemporary work being done elsewhere ; 
but such an account will be given by one who has 
gained a complete mastery of it at first hand for the 
purposes of his work, and will always be real, live, and 
interesting as compared with the account of one who 
has read it only to compile a text-book: or give a course 
of lectures. 
These ten lectures on recent advances in the physi- 
ology of digestion are an example of this, and are full 
of interest from start to finish, by which is not meant 
that one follows the author in a quiescent state of en- 
