1847.] Inorganic Matter lost in Drainage Water. 155 



evitably mar the crop. The hills should be not less than four 

 feet asunder; and in a very rich soil, a greater distance may be 

 better. The same of drills. 



5. The cuttings in drills, where the land is light, will answer 

 well at nine inches distance. This indeed seems to be a good 

 distance for the whites. But in rich land, and especially if the 

 potatoes are of the red kind, the stalk of w^hich grows to a larger 

 size than that of the whites, the distance should be not less than 

 twelve or fifteen inches. The red require richer land than the 

 white. 



If these observations contain any thing not generally known, 

 you are at liberty to lay them before the society. If not, the 

 communication you will please to suppress. 



LOSS OF INORGANIC MATTER IN DRAINAGE WATER. 



The following extract as it appears in the Gardiners' Chronicle, 

 furnishes matter for reflection. The loss of nutriment which is 

 sustained by deep drainage is probably large, at the same time we 

 believe the practice of thorough drainage will be sustained: 



In the autumn of 1844, being a resident in East Lothian, where 

 the system of thorough drainage is very extensively carried out, it 

 occurred to me that the drainage-water during its percolation of the 

 soil must necessarily dissolve out and cany away a great portion 

 of the soluble constituents of it, which by the practice as at pre- 

 sent followed, are carried off the land and entirely lost to the far- 

 mer. I therefore took advantage of the first fall of rain sufficient 

 to set the drains running after the dry weather of the autumn, and 

 collected some of the drainage-water, which I subjected to a par- 

 tial analysis, the particulars of which are described in a paper 

 read by Dr. W. Gregory, at a meeting of the Royal Society, Ed- 

 inburgh, in the early part of last year. The results I then ob- 

 tained, though very incomplete, were quite sufficient to show me 

 that they had a very important bearing on agriculture, and to in- 

 duce me to go on with their further investigation. About the 

 usual quantity of rain had fallen during the time between Novem- 

 ber, when I collected the first sample, and April 29th, when I ob- 

 tained the second, and during the whole of that period the land 

 had laid ploughed as a winter fallow. Immediately after the se- 

 cond sample was taken, the field was prepared for seed and sown 

 with guano and barley. In a few days after (May 16th), I was 



