DECEMBER 27, 1918] 
general laws of human energetics, have been 
long established. But details which are of 
great importance when any exact view of the 
subject is desired, still escape us. To express 
the energy requirements of agricultural labor- 
ers in terms of food with the precision attain- 
able by an actuary in estimating their average 
expectation of life is still an ideal of the re- 
mote future. This is only in part due to the 
greater difficulty of measuring energy trans- 
formations as compared with the measurement 
of longevity. It is now quite possible by 
means of relatively simple apparatus to carry 
out such determinations on a large scale. But 
the task is not one that any private investiga- 
tors can be expected to undertake. The mere 
compilation of statistics of family consump- 
tion, a less laborious affair, occupied much of 
the time of the United States food investiga- 
tors for years. Here is a proper object for the 
team work of which so much is heard in these 
times. It involves physiological skill both in 
making the measurements themselves and in 
paying due heed to the attendant circum- 
stances, such as the cooling power of the air 
in the factory or workshop, a point scarcely 
heeded by many past students; industrial 
knowledge is needed to decide what factory 
processes are in part materia so that repre- 
sentative samples may be chosen for experi- 
ment; lastly, some experience in the handling 
of numerical data is required to decide the 
significance of departures from the average 
and the limits of precision of the averages 
themselves. Nor does it suffice to enroll a suit- 
able team of investigators and send them out 
into the factories to collect data. The routine 
application of a physiological technique is the 
death of science. When a method is intelli- 
gently applied upon a large scale anomalous re- 
sults must emerge, the analysis of which upon 
a laboratory scale and with the attendant 
simplification of the conditions may lead to 
the discovery of new and important truths. 
The investigating staff must be attached to a 
headquarters laboratory controlled by a physi- 
ologist competent to sift real anomalies from 
mere technical errors and to cause them to be 
SCIENCE 
651 
sedulously investigated. We conceive that in 
this way alone a really adequate knowledge of 
the energy requirements of muscular work can 
be attained. 
When it is remembered that this problem, im- 
portant as it is, is only one of the problems of 
human nutrition which are still unsolved, we 
do not think more need be said in support of a 
national laboratory of nutrition. No doubt 
the time will come when the intelligent citizen 
will find it difficult to understand how any 
nation could neglect to make such a provision 
for its literally vital needs—British Medical 
Journal. 
SCIENTIFIC BOOKS 
An Outline of the History of Phytopathology. 
By Hersert Hick Wuerzer. Philadelphia 
and London, W. B.-Saunders Company. 
1918. Pp. 130, with 22 portraits. 
The domain of plant pathology is rapidly ta- 
king shape as a highly important part of the 
contribution of botany to the economic life of 
the world, as well as a department of botanical 
science demanding recognition from students 
of the modern aspects of science in general. 
The enormous losses which crops suffer from 
parasitic and predatory fungi have long been 
recognized in a general way, but only in re- 
cent years, since numerous investigators have 
undertaken to study the causes which inhibit 
the optimum development of cultivated plants, 
has the great diversity in the etiology of plant 
diseases been so clearly shown. With the rec- 
ognition of the diseases and their causes has 
grown up practical means for controlling or 
avoiding many of them. The economic returns 
have reacted upon the opportunities for in- 
vestigation, and consequently great progress 
has been made in this department of botany 
within the few decades just past, more espe- 
cially in America. The epidemic of the chest- 
nut blight, the fight against the white pine 
blister-rust, the barberry-wheat campaign, and 
the government and state quarantine acts 
against the importation of diseased plants, 
have brought the subject home to every one. 
The pioneer work by Professor H. H. Whet- 
zel, of Cornell University, on the history of 
