473 
who has stock to keep needs to know in order to feed most rationally 
and economically. A most excellent feature of the work is its price, 
which is only 24 marks, or about 60 cenis, gold. 
Another and equally useful work by the same author bears the title 
Praktische Diingerlehre, and contains just such plain, definite, and prac- 
tical information about fertilizers and manuring as the one just men- 
tioned gives about foods and feeding. It is also a small quarto of 
200 pages and is sold at the same price, 24 marks. It speaks of air, 
water, and soils as sources of food for plants, and explains the general 
principles of vegetable nutrition, and then describes the various import- 
ant fertilizing materials, their composition, value, and proper modes of 
application. If a farmer wants to know the characteristics of pure 
guano or bone, what they are composed of, how much phosphoric acid 
and nitrogen they ought to contain, and for what kinds of soils and 
crops and in what proportions they should be used, he has only to turn 
to the proper place in this book and learn. At the end he will find tables 
showing how much of the ingredients of plant-food are removed with dif- 
ferent crops and supplied with different fertilizers, and other data which 
will enable him to keep account with his soil and see how the supply, 
by artificial means, keeps pace with the exhaustion in cropping. How 
useful the German farmers find this little book to be for them may be 
inferred from the fact that the sixth edition has been published and 
that the circulation has reached some 10,000 copies. 
The spread and usefulness of this definite knowledge of the principles 
that lie at the basis of the right practice of farming is still better illus- 
trated in the farmer’s diaries in very common use among German farm- 
ers. One of these, bearing the title of ‘“‘ Mentzel and von Lengerke’s 
Agricultural Calendar,” is published annually in two parts, the one a 
pocket diary, the other for occasional reference, both together costing 
about 54 cents, gold. The amount of useful information and help in 
systematizing farm management which this little work contains is aston- 
ishing.. The pocket volume furnishes a diary blank for every day in the 
year; tables for labor accounts; forms for registering yield of milk from . 
each of sixty cows for each week of the year; seed and harvest tables ; 
hay and forage tables; threshing tables; tables for entering all pur- 
chases, sales, and increase of livestock ; tables for noting the destination 
of every kind of manure, and others for accounts of grist. Then come 
tables giving amounts by weight and measure of seed needed for a 
Prussian morgen, (about two-thirds of an acre,) either broadcast or in 
drills, for ninety-five different kinds and varieties of crops; amounts 
yielded per morgen of various crops, andso on. Then follow tables for 
calculating the exhaustion of soils by crops and enrichment by man- 
ures. These give the amounts of water, nitrogen, potash, soda, lime, 
magnesia, phosphoric acid, and so on, in not far from two hundred kinds 
of crops, and half as many kinds of manures, these latter being supple- 
iwented by tables for calculating how much stable manure will be 
produced per annum by a given number of animals; how to calcu- 
late the values of different commercial fertilizers from analyses, and so 
on. After these come still more elaborate fodder-tables, giviag the 
chemical composition of nearly 250 different kinds of food for stock, 
with the amounts of digestible substances in each ; the amounts of the 
digestible food-ingredients needed by different animals for dairy rations, 
and finally a long series of fodder-rations, or mixtures of the various 
tvods in the proportions in which they should be fed to different ani- 
mals, and for different purposes, in order to secure the most economical 
eee of the nutritive material they contain. This diary is largely 
A 
