28 IMPERIAL COLLEGE OF 
and straw ash, lime, and night-soil, so far as the latter is 
transported by associations of professional scavengers from 
cities into the country, where the manure is sold, or so far 
as it is directly purchased or exchanged against vegetables, 
wood, etc. by the farmer, who carts it home himself. The 
prices paid to the citizens for the night-soil are, of course, 
subject to great fluctuations according to the size of the city, 
the season of the year, the method of transport e. g., 
whetherby boat, by cart, etc. Hence it is quite impossible 
to calculate a reliable absolute value for a unit of nitrogen, 
phosphoric acid, or potash, contained therein. Of the other 
commercial manures above mentioned, dried fish, bran, and 
oilcakes, being distributed uniformly enough over the 
districts where agriculture is carried on intensively, afford 
a better basis for determining the money value of the 
principal vegetable nutrients in Japan. 
As to the relative value of these nutrients e. g., the 
proportion between the prices paid for them, it is, how¬ 
ever, at present quite impossible to arrive at any accurate 
figures. We must be satisfied with an approximate adjust¬ 
ment based on the valuations of them in other countries, 
and need not fear to commit any great error, since even in 
countries so different as Germany and the United States, 
the ratio between the values of the nutrients is almost 
invariably the same. There the extensive trade in concen¬ 
trated fertilizers has guided us to the establishment of 
certain scales which admit of an easy judgment as to the 
actual price of artificial fertilizers. In Germany according 
to E. von AVolff. the following prices in marks are paid for 
one kilogram of each nutrient : 
I. Nitrogen, in the form of ammoniacal salts and 
nitrates, or in easily soluble or de¬ 
composable organic substances, such 
as dried and powdered blood, flesh 
meal, Peruvian guano .1.40-1.60 
