Stored urine can be considered as a dilute solution of ammonimn carbonate with some organic and inorganie imnnrities.Nearly all its nitrogen aan be conserved by a close-fitting cover, or still better by a layer of lubricating oil. In so far as consesvation of nitrogen is concerned, mixing urine with air dry soil is ranch better than with organic matter. Treatment with oalcinm chloride is also more effective than that with gypsum.It is found that potassinrrrion exerts a very unfavorahle influence on the absorption of ammonium ion by soil colloid, whereas the effect of sodium ion is much leas. The fact that straw and wood ashes can not be mixed with mine earth,or soil compost rich in ammonia js not only due to the alkalinity of the ashes, but also due to the interforence of potasaimn ion on the absorption of ammonia by soil colloids.