930 



EXPERIMENT STATION RECORD. 



Some of the sterilized solutions were tested for Inicteria, but none 

 were found. The uniounts of amnioniii found were as follows: 



Amounts of ammonia found in different solutions {■'series 1 and 2). 



a Bv iSTesslcr's rcaKi'iit witlioiit ilistilbitiim. 



Sej'ies ;> (control experiments) was examined after 2 to 4 months. 

 No ammonia was found. 



The results obtained in series -t were as foUows: 



Ammonia found in series 4- 



In all cases the ammonia was determined without previous decom- 

 position of the humus which, as is well known and as the author proved 

 by special experiments, retains ammonia. The above figures for 

 ammonia are, therefore, too low. 



Without making special claiius for the accuracv of the quantitative 

 determinations the author draws the following conclusions: 



(1) Humus, as well as the ferrous salts, is al)le to reduce nitrate of 

 potash to ammonia. 



(2) This reduction proceeds very slowly at ordinary temperatures, 

 })ut l)ecomes more rapid on heating. 



(8) Caustic alkali and free access of air do not destro}' the ability of 

 humus to reduce nitrate. 



(-t) Thus the possi])ility of denitrification of nitrate of potash in the 

 soil under the influence of humus, without ])acteria, is fully corrobo- 

 rated by laboratory experiments. — p. fireman. 



Fertilizer experiments -with different sources of phosphoric 

 acid, If. .1. Pattki!S()n (JA/zv/A/y/^/ A'A/. />///. OS^j>jk 20). — An account 

 is here given of experiments hegiiii in the spring of 1895 on tcMtth-acre 

 plats of modei-ately stiff clay natuially well drained, to test the com- 

 parative availability of doul)le superphosphate (soluble and reverted), 

 dissolved boneblack, dissolved South Carolina rock, iron and alumina 

 phosphate (reverted), boneblack, raw bone meal, slag phosphate, 

 ground South Carolina rock, and Florida soft phosphate. These 

 different phosphates were each applied in amounts furnishing 150 

 lbs. of phosphoric acid per acre. The bulletin gives a discussion of 



