26 
Colorado Experiment Station. 
There JVas Some Difficulty With Sand. 
The total ash is high compared with the average, but when tli 
sand and silicic acid are subtracted, the results are very close to thos 
of the standard analysis. One of the difficulties with a few of th 
older samples of the cow manures was the presence of large amounl 
of sand and gravel which had been blown or trampled into them. Li' 
erally a quart or two of gravel had to be picked out of some of tli 
samples before anything in an analytical way could be done with then 
For this reason the sand and silicic acid were carefully determined i 
the ash, although some of the silicic acid belongs to the ash of th 
manure as it was a constituent of the plants the animals fed upon. 
The Soluble Portion is Nearly a Constant Quantity. 
While discussing the soluble and insoluble ash in sheep manure, 
was stated that the soluble ash did not increase with age, but remaine 
near 7 percent. This is also the case with the cow manures, excel 
that the soluble ash amounts to about 5 percent. This probably poini 
to the fact that the manure can retain about that amount of soluble asl 
the rest being lost through leaching. We know from many exper 
ments, some of which have already been cited in connection with tl 
discussion of sheep manure, that all manures lose rapidly in 'bulk an 
weight when exposed to the weather, and an increase in the ash coi 
tent, soluble as well as insoluble, should take place, but we find th; 
the soluble ash remains constant. The loss consists chiefly of solub' 
salts and liberated gases, such as carbon dioxide and nitrogen, cause 
by the action of micro-organisms. From the results given in Table I\ 
it would seem that almost the whole of these soluble salts are lo 
since the manure retains only about 5 percent no matter how old it i 
This loss is principally due to leaching, for some of our rainfalls ai 
heavy, and sometimes extend over a considerable period. 
Solubility of the Nitrogen, Potash and Phosphoric Acid in Water. 
It was so unusual to find the potash retained by the manure to 
greater extent than the nitrogen, that 200 granis of manure No. 1 
were extracted with water, and the potash and phosphoric acid d< 
termined in the extract. 
After washing with water there remained 164.4 grams of manui 
making a loss in the extract of 17.8 percent. The nitrogen was d<| 
termined in the residue and in the original sample, the former givin 
1.817 percent and the latter 1.125 percent, a difference of 0.692 pe 
cent, which was the amount soluble in water. The phosphor 
acid in the soluble portion amounted to 0.265 percent and the potas 
to T.700 percent calculated on the air-dry manure. This shows coi 
clusively that it was not because the potash was held as some insolub 
