AvuGUST 15, 1912] 
NATURE 
605 
public health students, and deals with the analysis 
of water, foods, beverages, soil, air, and disinfec- 
tants, with chapters on microscopy and meat 
inspection. The directions are clear and concise, 
and adapted for the examination for the diploma. 
The reactions are shortly explained, and examples 
of calculation given. 
Several errors in the 1900 edition appear again, 
e.g. iron alum is given as (NH,),Fe(SO,),6H,O. 
‘On page 63 NO, should be N,Os, and on page 134 
a drawing of manilla hemp (Musa textilis) is given 
under a description of ordinary hemp (Cannabis 
sativa). 
necessary for the detection of boracie acid in milk, 
and that the addition of potassium permanganate 
in the Kjeldahl process is neither necessary nor 
advisable. 
omissions of some modern processes, the book may 
be recommended as a useful laboratory com- 
panion for public health students. 
(2) This book is divided into three parts, “The 
School,” “The Scholar,” and ‘“‘ The Medical Super- 
vision of School Life.” 
in a practical, common-sense manner on a 
physiological basis. There are chapters on 
elementary physiology, so that readers without 
previous physiological training may appreciate the 
reasons for the hygienic conditions demanded. 
The important subject of ventilation is well 
treated, the standard demanded high, but not 
impossible. In the chapter on foods and digestion 
it is a relief to note that food-testing has not been 
included, as is so often done in books on hygiene 
with unsatisfactory results. In this chapter, how- 
ever, fats are wrongly described as hydrocarbons, 
and ptyalin is said to convert starch into grape 
sugar instead of malt sugar. The book is read- 
able, and may be recommended to teachers and 
others as a practical and useful text-book. 
(3) Almost the first of its kind, this book deals 
mainly with experimental work in foodstuffs, and 
is intended for use in domestic science schools. 
The aim is admirable, and much of the book is 
excellent, but in attempting simplicity experiments 
are described and results stated that will tend to 
perpetuate just the types of error and inaccuracy 
that are already too prevalent. On page 20 the 
author appears satisfied with results that vary 
from 12 per cent. to per cent. The conclusion 
25 
arrived at from another experiment is that cream | 
has the same specific gravity as water. It is 
difficult to say how far we are justified in sim- 
plifying experiments at a sacrifice of accuracy and 
truth, especially for those who are not in a posi- 
tion to examine the results critically. 
A number of errors occur, e.g. the boiling of 
milk several times is described as pasteurisation. 
NO. 2233, voL. 89| 
One might mention that ashing is not | 
We are told that the tannin of coffee precipitates 
gelatine, and that potassium palmitate and stearate 
are soft soaps. In a book written for students 
| who have little or no training in science, accuracy 
| and caution in interpreting results are most impor- 
tant. However, the book contains many good 
suggestions for this kind of work. 
OUR BOOKSHELF. 
The Effects of Errors in Surveying. By Henry 
Briggs. Pp. xi+179. (London: Charles 
Griffin and Co., Ltd!, 1912.) Price 5s. net. 
(Griffin’s Scientific Text-books.) 
Tue author of this volume directs attention to 
| the inadequate treatment of errors in surveying as 
compared with astronomical, physical, or chemical 
Pp > y > 
| research, and offers the present work as a discus- 
In spite of a few such errors and | 
sion of the subject from the special point of view 
of the surveyor. His contention is perfectly valid, 
and the cause of this neglect may be traced to the 
very small amount of instruction in the highest 
| grades of surveying which is given in this country. 
It deals with the subjects | selected for use in the book as being simpler and 
The analysis of error forms an _ introductory 
chapter, and in it the average error has been 
more convenient, though we are inclined to doubt 
whether the advantage of the mean error in giving 
greater weight to the large errors in a series is 
advisedly abandoned. The best shape of triangles, 
the propagation of errors in traversing, with 
especial reference to mining surveys, and in 
triangulation, occupy most of the volume. 
The book is clearly written, and will lead to 
an improvement in the work of surveyors if it 
brings home to them the desirability, as well as 
the economical advantage, of systematically de- 
termining the errors of the methods which they 
adopt, as well as of the observations which they 
make. An equally desirable result would be the 
incorporation in all manuals of surveying of a con- 
sideration of the errors to be anticipated in all 
surveying operations, both in the simpler kinds and 
in the more advanced; for this should be as normal 
a feature of such works in this country as it is 
on the Continent. This same mathematical de- 
| termination of errors should also find a regular 
_ place in the compilation of maps and plans as a 
control upon the empirical methods which are too 
exclusively employed at the present time. 
He iGs 1: 
Der Mythus von der Sintflut. Von Georg Gerland. 
Pp. vitz24. (Bonn: A. Marcus und E. 
Weber’s Verlag, 1912.) Price 3 marks. 
In this little work Prof. Georg Gerland has 
published an interesting study, on comparative 
lines, of the different deluge-myths which occur 
in the traditions of many races all the world over. 
| He first gives an outline of the various forms under 
which the legend is encountered, arranging his 
material on a geographical basis. As is natural, 
he begins the series. with the “Western-Asiatic- 
Semitic’ accounts, analysing the Biblical narra- 
tives and indicating the extent of their depend- 
