EXAMINATION OF FROZEN EGG PRODUCTS. 83 
TABLE 36.—Ammonia nitrogen obtained by use of Duboseq and Schreiner colorimeters in 
the nesslerization method. 
R Ammonia nitrogen. Ammonia nitrogen. 
aS Tuitial of Sam- | Initial of 
R 5 analyst. ple analyst. | 
: Duboseq.|Schreiner.| Titration. No. Duboseq./Schreiner.| Titration. 
Mg. per | Mg. per | Mg. per Mg. per | Mg. per | Mg. per 
100 grams.\100 grams.\100 grams. 100 grams.|100 grams.|100 grams. 
TA N(R ee ae 15) 1.2 2.0 66 {g MeeVee Talo clove 1.8 1.4 2.9 
AGH Bees oe eee 1.6 13 1.9 BU IS cea ect 3. 0 2.8 Bol 
Aiba SEB atee Sele cess 1.9 15 2.2 lee eee 2.0 2.0 2m 
ANGST |) SSP a eee eee Pei 1.8 2.8 Gia Ele asee see: 2.3 2.5 2.5 
Shall Be ero aaa 4.6 3.9 4.5 Seosaue ones 2.4 252 22: 
ID) Ge te Sete ae 3a PX 3.0 esas eSece 23 2.3 2.4 
GOR eee ees PES 2h 2.6 UO:lhyis be Se te ease 2.7 Qn! 2.9 
Ae hae e Mere 2.6 1.8 3.0 Sic eee 2.7 253 2.8 
ID Ae eres 2.9 2.4 2.8 | DR Beem 7.0 6.8 Utd 
GI See eee ee se 2.4 2.5 2.6 Wd isleee eaauae 8. 0 6. 6 6.6 
15 [jsp gente 3.0 2.4 3.0 Sree agacee 8.2 8.5 8.1 
ID) eee Ee 6.3 6.0 6.9 1D ease nee 6.5 6.1 4,2 
G2 iWaseee cia 2 6.1 6.7 6.5 GS e le asmamene 3.7 2.8 4,9 
ees ge 6.5 5.9 6.8 Sian eeu se 5.5 5.3 4,5 
10s Sees 9.9 8.2 Sie. O . I aee SB See al 6.5 6.7 4,4 
G33 Kdieoeesoreeoe 7.0 8. 0 8. 0 69 1 Sacer 4.5 4.5 5.0 
lel Saar 7.8 8.2 8.7 Shas. tee 5.7 4.9 4,7 
Dates eve is 3 2.3 25a 2.6 IDeasacosaeee 252 2.1 Zoli 
AGN SIR eerste co -- Dl 2.2 2.4 CO hile lets Seeealase 2.4 1.5 2.1 
13 Oe io ele 2.0 1.4 Qh. Se Bbeeeesese 2.9 2.4 2.4 
ID Aes sera Qe 2.0 2.8 iD paar sees 2.5 2.4 PI 
75 {2 ce eet Ie 2 2.0 2.9 71 fs Ba iors Sis 2.4 1.8 2.5 
IOs igs 255 1.5 2.3 SSaue a eamaae 2.4 2.1 2.4 
IDSA Bete 2.4 2.4 252 HU SSR SE eis 207, PAST 2.5 
Cae He See 2.3 2.1 2.3 72 { ne see 4.5 3.1 2.8 
Shas wes wens 2.4 2.0 2.8 Sees gaa es 2 PRT 2.3 2.8 
EE eae ne, gee 2.4 2.3 2.3 Tae he areas = 3.3 3.2 PET 
Gog screg ee eee 1.9 1.6 2.8 73 fs BS eeM a Se $2240 1.4 3.2 
IS) ase nen 2.8 253 2.6 Sasa agaaeses 3.0 3.6 3.1 
GG | Wiscecakecece Py UF Qe 3.0 
From Table 36 it is evident that the Schreiner instrument may 
not be substituted for the Duboscq colorimeter, since it gives results 
which are in the majority of cases decidedly lower than those 
obtained with the Duboscq instrument. By comparing the nessler- 
ization results with the titration results, it will be seen that the 
results with the Duboscg colorimeter are too low and that the results 
with the Schreiner, which are still lower, are decidedly inaccurate. 
NESSLERIZATION MrtHop FOR AMMONIA NITROGEN. 
Dissatisfaction with the nesslerization method for the determination 
of ammonia nitrogen was expressed by the chemists throughout the 
cooperative work, not only because of the lack of uniformity of results, 
but also because of mechanical difficulties in the method. Much 
trouble was experienced with foaming. At first this was overcome - 
to a large extent by adding a few.cubic centimeters of amyl alcohol, 
but this method has the disadvantage that the amyl alcohol, due to 
its volatility, often must be added more than once during the aera- 
tion, and also it has a tendency to give a slight blank reading. 
Later very heavy cylinder oil was used successfully to prevent foam- 
ing. Recently one of the analysts reported in connection with 
some determinations made on samples subsequent to the coopera- 
