DECEMBER 1, 1899. ] 
section of Professor Abbe’s paper concerns Cli- 
matology and its Aims and Methods, and deals 
chiefly with the relations of climate to vegeta- 
tion. Some years ago Professor Abbe made a 
careful study of the latter subject, and, al- 
though he has never published any extended 
report upon it, he has often referred to the re- 
sults to which his studies led him. We take it 
that these pages of the Maryland Weather Ser- 
vice volume contain a summary of the results 
which Professor Abbe reached, and we welcome 
them as giving the best brief statement of the 
most important facts in the complicated inter- 
relations of climate and the products of the 
soil. Soil temperatures ; the climatic influence 
of forests and agriculture; reforestation ; the 
geographical distribution of plants, etc., are 
considered. The third section of Professor 
Abbe’s report deals with Apparatus and Methods, 
and is the first publication on this subject we 
have yet seen which illustrates the different 
instruments altogether by means of photo- 
graphic reproductions. 
A Sketch of the Progress of Meteorology in 
Maryland and Delaware, by Dr. Fassig, follows, 
and is an extremely interesting historical ac- 
count. We note, in passing, that Dr. Fassig 
reproduces Lewis Evans’s map of 1749, which 
contained the famous statement concerning the 
movements of northeast storms from the south- 
west. A copy of the original map, published 
in 1747, Dr. Fassig was unable to find; he has 
therefore reproduced the second map, dated 
two years later. Credit has sometimes been 
given to Evans for the first statement of this 
important discovery, but it justly belongs to 
Franklin, as Dr. Fassig says. This paper con- 
tains a valuable bibliography of publications 
relating to the climatology of Maryland. 
The final report, by Mr. F. J. Walz, an Out- 
line of Present Knowledge of the Meteorology and 
Climatology of Maryland, is a very complete ac- 
count, containing full tables and many figures 
and charts. We note, with pleasure, a classi- 
fication of Maryland weather into types, illus- 
trated by means of weather maps, for clima- 
tology does not become a living study until the 
weather phenomena which go to make it up 
are understood. Mr. Walz has given us a cli- 
matic account of Maryland which is brought 
SCIENCE. 
817 
quite down to date, and which may well be 
adopted as a model by those who discuss the 
climates of other states. Excellent shaded 
charts showing precipitation and isotherms for 
each month, for the seasons, and for the year, 
accompany the report. Figures 35-40 are new. 
They are weather wind roses, and show the 
weather and wind conditions when Baltimore 
is under the influence of a cyclone and anti- 
cyclone in different seasons. Figure 55, the 
advent of spring in Maryland, is also an inter- 
esting addition to our knowledge of the climate 
of the state. 
We have exceeded the limits which we set 
for this review at the outset, but we believe 
that the volume under discussion has been 
given no more space in this JOURNAL than it 
deserves. Paper, press-work and illustrations 
are all of the highest grade. 
R. DEC. WARD. 
HARVARD UNIVERSITY. 
Indicators and Test Papers, their Source, Prepara- 
tion, Application and Tests for Sensitiveness. 
By Aurrep I. Conn, Pu.G. New York, 
John Wiley & Sons. 1899. Pp. 224. 
As stated on the title page, this work is ‘‘a 
résumé of the current facts regarding the action 
and application of the indicators and test papers 
which have been proposed from time to time, 
and are in present use in chemical manipula- 
tions.’’ 
Part I. (pp. 19) deals with the general con- 
siderations determining the choice of indicators, 
their applications and limitations, behavior in 
other than aqueous solutions, dissociating effect 
of solvents, theory of their action, ete. 
Part II. (pp. 154) is devoted to a discussion 
of a great number (76) of indicators, including 
not only those in common use, but also a great 
many others whose use has been recommended 
from time totime. The arrangement is alpha- 
betical throughout, the data for each indicator 
being arranged under the following headings : 
Synonyms, Source, Preparation, Properties, and 
Application. , 
Part III. (pp. 51), on Test Papers, records the 
preparations and properties of 74 varieties, and 
is followed by tables showing the relative sensi- 
tiveness of indicators and test papers, and a 
