JUNE 17, 1915] 
NATURE 
425 

temperature regulators and air conditioning. 
The sections dealing with the amount of heat 
required for warming and with the heat given off 
from radiating surfaces are of special interest. 
It must, of course, be understood that the efficient 
warming of a large building is a matter that is 
not susceptible of absolute mathematical calcula- 
tion, and a great deal of the measure of success 
attained lies in the manner in which the warming 
and ventilating appliances are handled by those 
in charge. The volume before us has proved 
in the past to be a useful guide to architects and 
others responsible for providing the arrangements, 
and with the information which it now contains 
will no doubt prove equally useful in the future. 
Structural Steel Drafting and Elementary Design. 
By C. D. Conklin, Jr. Pp. vii+154. 
York: J. Wiley and Sons, Inc. ; London: Chap- 
man and Hall, Ltd., 1915.) Price ros. 6d. net. 
THE author’s object in compiling this book has 
been to provide a treatise dealing adequately with 
the preparation of shop detail drawings of struc- 
tural steel work. Such a book is required no less 
in Great Britain than in the United States. In 
both countries there are several very good books 
dealing with the design of structural steel work. 
Some of these contain excellent expositions of 
the more theoretical work, but they do not meet 
the requirements of the practical draughtsman, 
and speaking generally, leave the reader with 
a very small knowledge of structural details. 
The book before us gives a clear and minute 
description of the methods adopted in some 
leading American drawing offices, and includes 
designs of riveted connections, beams and 
columns, steel roofs, a deck plate girder railway 
bridge, a through girder bridge, etc.  Fully- 
dimensioned working drawings are given as well 
as the simpler calculations required in the design. 
The book is thus suitable for use in technical 
colleges, and provides a fairly complete course 
in structural drawing office practice. With a 
few minor modifications, which the teacher can 
easily supply, the book can be brought into line 
with British practice and nomenclature, and ought 
to be of service to students of structural steel 
work in this country. 
Calculus Made Easy. By F. R. S. Second 
Edition. Pp. x+265. (London: Macmillan 
and) Gommletd:. 1914-)) Pricesessinet: 
Tue author of this book has added many worked 
examples and exercises to those in his first 
edition ; otherwise the book is but little altered and 
we have not much to add to the remarks we made 
five years ago. The motto is, “ What one fool can 
do, another can.” Perhaps there may still be 
too many encouraging remarks of a jokesome 
nature and too many expressions of disdain for 
the stupidity of the usual methods of teachine. 
but the title of the book is justified. The author 
does show that the most fundamental operations 
of the calculus are easy to understand and may 
be performed by beginners with success, that is, 
without vague notions of being wrong. J. P. 
NO. 2381, VOL. 95] 
(New | 

i 
LETTERS TO. THE EDITOR. 
[The 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 intended for 
this or any other part of Nature. No notice 1s 
taken of anonymous communications. | 
Surface Tension and Ferment Action. 
Messrs. BEARD AND CRAMER, in a paper under the 
above title published in the Proceedings of the Royal 
Society issued on June 1, describe experiments made 
with invertase with the object of determining 
‘“whether the action of a ferment on a substrate is 
affected by surface tension.’’ They answer this ques- 
tion in the affirmative and draw far-reaching con- 
clusions. 
The method they use, however, is open to very 
serious criticism; we think that there is little doubt 
that the phenomena they describe are due entirely to 
the effect of alkali and not to change of surface ten- 
sion. They have compared the activity of invertase 
towards cane-sugar in tubes filled either with glass 
wool or with capillary glass tubes or with glass beads 
with that of a control in an ordinary test-tube. Re- 
tardation of action was observed in all such cases. 
All who have experience in working with saccharo- 
clastic enzymes are well aware how extraordinarily 
sensitive these are to the influence of the minutest 
trace of alkali. This applies to the enzyme invertase 
in particular. In a paper published in the Proceed- 
ings of the Royal Society so far back as 1907 (Series 
“By” p. 362) we pointed out that unless hard glass 
vessels were used, it was impossible to obtain consis- 
tent results; in fact, it is not only necessary to carry 
| out the action in hard glass vessels but it is essential 
also to use storage bottles and measuring pipettes of 
similar hard glass: even then the results are apt to be 
irregular. 
The work done by Sérensen in co-ordinating enzyme 
activity with the degree of alkalinity or acidity of 
the medium is too well known to need description ; his 
experience with invertase shows clearly how much the 
activity of the enzyme is influenced by the minutest 
trace of allsali. We look in vain in Messrs. Beard 
and Cramer’s paper for any reference to the possible 
influence of alkali derived from the soft glass they 
used as a cause of retardation; it would appear that 
they have entirely overlooked this factor. So long 
as no definite evidence is brought forward to show 
that the retardation change they observed is not due 
to the action of alkali, it is unnecessary to attribute 
it to the influence of surface tension. 
E. F. ARMSTRONG. 
H. E. ARMSTRONG. 

Training for Scientific Research. 
IN connection with our position in regard to chemi- 
cal industry, the present seems to be a suitable time 
for a careful discussion of what is doubtless not a 
new suggestion. It is a sufficiently obvious fact that 
the German chemical trades—especially those that 
most require highly-trained chemists—-prosper in very 
much greater measure than our own, and, by general 
consent, the reason for this appears to be that the 
Germans appreciate the value of research more than 
we do. How then is a better appreciation of research 
to be fostered in this country? Various proposals to 
this end are being made; closer relationship between 
technical and theoretical chemistry, whatever that may 
mean; the establishment of an industrial council; the 
founding of scholarships, etc., all, doubtless, good 
things in their way, things, however, which have been 
