6 
The Colorado Experiment Station. 
the air dried hay or fodder, this method has the patent advantage 
of giving every percentage upon a basis which can be easily dupli¬ 
cated within quite narrow limits which we found would be attended 
with considerable difficulty if we used the weight of the extracts 
obtained, as each one showed a deficit for which we could not ac¬ 
count. The weight of the residual portion of the hay seemed, fur¬ 
thermore, to be less subject to change, debarring the absorption of 
moisture which is comparatively easily guarded against, than that 
of the extract. 
§7. As already stated, the boiling, 80 per cent, alcohol ex¬ 
tracted the hays readily and even the first portion removed prac¬ 
tically all of the coloring matters which, particularly in the case of 
alfalfa, was large and difficult to remove from the extract. 
§8. It was not possible for us to prosecute any examination 
of these coloring matters, but it was necessary that we should re¬ 
move them completely from the solution before we could proceed 
to test for sugars. The matter of decolorizing these solutions 
proved to be a difficult one. I first tried the effect of adding potas- 
sic aluminate and the precipitation of the aluminic hydrate by pass¬ 
ing carbon-dioxid through the solution. My idea was that the pre¬ 
cipitating aluminic hydrate might carry down all of the coloring 
matter, this, however, did not prove to be the case and the filtrate 
from the AI2 (O had a bright yellow-red color. We pursued 
this a little further but the results, while interesting in themselves, 
did not advance the work in hand. 
§9. Though I desired to avoid the use of basic acetate of 
lead, it proved to be the most effective agent in removing the yellow 
coloring matter, the filtrate however, was green and worked badly 
with the Fehling’s solution, yielding a flocculent precipitate which 
may have contained cuprous oxid, it probably did, but the precip¬ 
itate was essentially something else. We found that the addition 
of cupric sulfate removed the green coloring matter completely, 
yielding a colorless solution, provided no excess of the cupric sul¬ 
fate had been added. The use of the basic acetate of lead and cu¬ 
pric sulfate worked well. 
In Bulletin 39, I recorded the observation that the reducing 
power of such extracts are greatly diminished by the addition of 
basic acetate of lead but that I failed to detect any sugar in the pre¬ 
cipitate. 
§10. In the present work, it was imperative to establish one 
fact, i. e., that the combined use of the lead and copper salts did not 
in any way affect the quantity of sugar, sucrose, present either by 
removing it with the precipitate or causing its inversion. 
§11. In order to establish this point, several portions of the 
extract which had been made up to a given volume, after the alco- 
