84 BULLETIN 846, U. S. DEPARTMENT OF AGRICULTURE. 
tive work that the nesslerization method caused difficulty, although 
the reagents used were the same-as those which had given satisfactory 
results a few months before. He considers the method too uncertain 
on account of the foaming and sometimes also turbidity to meet with 
general approval. 
The consensus of opinion of those who participated in the work 
here reported is that while the nesslerization method for ammonia 
nitrogen in frozen-ege products may, because of the shorter time 
which it consumes, be of value, it is not nearly as accurate as the 
titration method, which is preferable where absolutely dependable 
results are required, as, for example, in analyses where court. action 
may beinvolved. If the nesslerization method is used for this purpose 
it should be run in triplicate_and the average result employed. 
STRENGTH OF ALUMINA CREAM TO BE USED IN THE ReEDucING SUGAR DETERMI- 
NATION. 
During the course of the work the question arose as to whether, 
if alumina cream was kept in a large contaimer and was not always 
shaken to a homogeneous mixture before a portion was removed 
for use, the results would be affected by the use of cream of varying 
concentrations. To decide this, alumina cream of regular strength 
was prepared, and it was used as such-and also after dilution with 
varying amounts of water. The results are shown in Table 37. 
TABLE 37.—Reducing sugar obtained with alumina cream of varying strengths. 
100 ce. 75 ce. 50 ee. 20.Ce: 
alumina | alumina | alumina | alumina 
Initial of analyst. cream, cream, cream, | cream, 
C ce. ee 50 ee. (ee: 
water. water. water. water. 
— SE SS SSS ||| eee 
EE eee cie ere ta Aas tis wicis Stal Seraeio Sela ei tate io ial= Siwsate eines neler eae 30 
13} sGanesScd cbc quenepeaaeD ua UU HE QUMaGenn oan odsos boaneosesoadads 3 - 30 3h. 32 
Pee eons sre a and a: Ae agen a ray Pe ga rR re ae raat ery Siege a 38 . 36 37 37 
Dee roe icine sate isos wpe clorsmtely sraei ate claps ote nine = ens nee relatos . 36 36 38 36 
A ee ee ea eee gee we are Site whats ister eal ots o weitere cw isa Ses teate 508) |Possormeee 32) | see eer 
LS ee Ue Cn ey SOE EC Re i Se er RR Re eee Sree RUGS | eee 1S te ee ae 
1 ta eis a ae AC eS CEE RSCOE SEC CISC DOCH OR IER aco ere cic CB dal eh eat es ce oe Bers ea 
13 elie ee ee Rie nee Bale eA AOR SR os Samana eee Seen eas a oe 30 «36 34 39 
Dee ees tee Saute See tees alec tc mracte Secs ciao en ne Soames 32 33 34 32 
These tabulated results prove conclusively that the concentration 
of the alumina cream has no influence. 
CHoIicE BETWEEN SULPHURIC AND HyprRocHLoric ACIDS IN THE DETECTION OF 
INDOL AND SKATOL. 
Experiments proved that sulphuric acid is preferable, because it 
gives more distinct colorations. 
r 
