270 BOARD OF AGRICULTURE. 



seven kinds of guanos and mineral fertilizers, ten sorts of 

 superphosphates, designated b}^ the material from which they 

 are made, and twelve grades of potash salts. 



A third table informs us what 1,000 pounds of barley and 

 fifteen pounds of hops are separated into in the beer manufac- 

 ture, how many pounds of spirits, grains, spent hops, etc., 

 result, and how many pounds of water, nitrogen, potash, 

 lime, phosphoric acid, etc., exist in each and all of these 

 materials. This table also gives the corresponding products 

 and their composition in case of the manufactures of yeast, 

 of wheat flour, of cheese, of beet sugar, and of flax. 



The experiment stations have, by their numerous exact 

 trials, furnished us with rules for calculating from the rations 

 of the animals the composition as M^ell as -the quantity of 

 stable manure which is furnished by the different classes of 

 live stock. 



* 



By aid of the tacts thus made accessible to him, the German 

 farmer can and does economize the resources of his soil, of 

 his manure yard, and of the fertilizer market to a degree that 

 was simply impossible twenty years ago. He can acquire as 

 clear an idea of the state of his soil as to crop-producing 

 capacity, as to what it needs and what it is already possessed 

 of, as he has of his bank account. He can learn whether any 

 course of cropping actually carried out in the past or proposed 

 for the future has removed, or will remove, more or less 

 potash, phosphoric acid, sulphuric acid, etc., from the field 

 than the field has received in manures, or will be likely to 

 yield without disturbing the equilibrium of its stores of plant 

 food . 



This cannot be done from these tables alone by any one 

 who is merely able to read them or to reckon by rule of 

 three, any more than the nautical almanac will enable the 

 ship's cook to find latitude and longitude ; but the tables give 

 to the farmer who is moderately instructed in the now received 

 doctrines of agriculture, in the matter of crop-production, 

 the data for finding where he stands in relation to his soil and 

 his crop, just as the tables for the latitude and longitude 



