NIGHT-SOIL. 195 



ducted the Chinese a thousand years since to dis- 

 coveries, which have been the envy and admiration 

 of Europeans for centuries, especially in regard to 

 dyeing and painting, and to the manufactures of 

 porcelain, silk, and colors for painters. These we 

 were long unable to imitate, and yet they were dis- 

 covered by them without the assistance of scientific 

 principles ; for in the books of the Chinese we find 

 recipes and directions for use, but never explanations 

 of processes. 



Half a century suflSced to Europeans not only to 

 equal but to surpass the Chinese in the arts and 

 manufactures, and this was owing merely to the ap- 

 plication of correct principles deduced from the study 

 of chemistry. But how infinitely inferior is the agri- 

 culture of Europe to that of China! The Chinese 

 are the most admirable gardeners and trainers of 

 plants, for each of which they understand how to 

 prepare and apply the best-adapted manure. The 

 agriculture of their country is the most perfect in 

 the world; and there, w^here the climate in the most 

 fertile districts differs little from the European, very 

 little value is attached to the excrements of animals. 

 With us, thick books are written, but no experiments 

 instituted; the quantity of manure consumed by this 

 and that plant is expressed in hundredth parts, and 

 yet we know not what manure is ! 



If we admit that the liquid and solid excrements 

 of man amount on an average to IJ lb. daily (| lb. 

 of urine and ^ lb. faeces), and that both taken to- 

 gether contain 3 per cent, of nitrogen, then in one 

 year they will amount to 547 lbs., w^hich contain 

 16*41 lbs. of nitrogen, a quantity suflScient to yield 

 the nitrogen of 800 lbs. of wheat, rye, oats, or of 900 

 lbs. of barley. (Boussingault.) 



This is much more than it is necessary to add to 

 an acre of land in order to obtain, with the assistance 

 of the nitrogen absorbed from the atmosphere, the 

 richest possible crop every year. Every town and 

 farm might thus supply itself with the manure, which, 



