254 Irrigation and Drainage 



large amounts of poisonous products from factories 

 in the form of injurious chemical compounds. 



The organic matter of sewage, in both its soluble 

 and finely divided, suspended form of solids, when 

 sufficiently diluted with other water, is of the highest 

 value as a fertilizer for many crops, and in all 

 warm climates it is often practicable and very de- 

 sirable to use such water for this purpose. 



Reference has already been made to the use of 

 sewage waters from the city of Milan on the water- 

 meadows of Italy. The far-famed Craigentinny 

 meadows, outside of Edinburgh, are another emphatic 

 illustration of the value of sewage in the production 

 of grass, and Storer, after visiting them in 1877, 

 writes as follows: 



"In 1877 there were 400 acres of these ' forced 

 meadows ? near Edinburgh, and they are said to in- 

 crease gradually. The Craigentinny meadows, just 

 now mentioned, were about 200 acres in extent, and 

 they had then been irrigated 30 years and more. 

 They were laid down at first to Italian ray grass 

 and a mixture of other grass seed, but these arti- 

 ficial grasses disappeared long ago, couch-grass and 

 various natural grasses having taken their place. 

 The grass is sold green to cow -keepers, and yields 

 from $80 to $150 per acre. One year the price 

 reached $220 per acre. They get five cuts between 

 the 1st of April and the end of October. This farm 

 of 200 acres turns in to its owner every year $15,000 

 to $20,000 at the least calculation, and his running 

 expenses consist in the wages of two men, who keep 



