Marcu 15, 1912] 
organic nitrogen present came from materials 
rich or poor in that element is discussed. 
H. G. Bexu: Fertilizer Economics. 
Advantages of mixed fertilizer are brought 
forth. 
The fertilizer industry an essential factor in the 
business and life of the country. 
European and American yields on wheat, oats, 
barley and potatoes are compared, showing Europe 
far ahead in crop yields. 
North Atlantic states compared with middle 
Atlantic states shows gains for north Atlantic 
states in yield per acre due to rational use of 
mixed fertilizer. 
Records of large gains by using fertilizer are 
given in Indiana and Ohio. 
Sound economie principles as the basis of manu- 
facture and sale of fertilizer are considered. 
HE. B. Hart: The Sulphur Requirements of Crops 
in Relation to the Soil and Air Supply. (From 
the Laboratory of Agricultural Chemistry, Uni- 
versity of Wisconsin.) 
The average crop of cereal grains and straws 
removes about two thirds as much sulphur as 
phosphorus, mixed grasses remove the two in about 
equal proportions, while alfalfa removes about 60 
per cent. more sulphur than phosphorus. Members 
of the Crucifere, such as cabbage and turnips, may 
remove two to three times as much sulphur as 
phosphorus. 
The superior results often obtained in the case 
of acid phosphate as compared with other sources 
of phosphoric acid may not be due entirely to the 
solubility of the phosphoric acid, but also to the 
additional sulphur supplied by the acid phosphate 
in the form of calcium sulphate. The idea that 
sulphur may become a limiting element in crop 
production would further account for the beneficial 
results obtained from gypsum, sulphate of potash 
and other sources of sulphur commonly contained 
in fertilizers. 
J. P. Srreet: Note on the Neutral Permanganate 
Method for Availability of Organic Nitrogen. 
The adding of one gram of sodium carbonate to 
the neutral permanganate solution just before 
adding material to be tested largely overcomes the 
loss in availability when high-grade ammoniates 
are mixed with large proportions of acid phos- 
phate. 
Results on many organic ammoniates in presence 
of acid phosphate are given, showing that the 
method does differentiate between high and low 
grade materials. 
SCIENCE 
427 
A. J. Patton and ©. 8. Ropinson: Conductivity 
Method of Making Neutral Ammonium Citrate 
Solution. 
This method, worked out independently by the 
authors, is essentially the same as that proposed 
in the meantime by Hall and Bell and later shown 
by Hall? to be quite suitable for ordinary labora- 
tory use, and their results are fully confirmed by 
this work. In addition comparative determina- 
tions of insoluble phosphoric acid were made, 
using solutions neutralized by the conductivity 
method and by the indicator method. The data 
justified the conclusion that the conductivity 
method is much to be preferred in every way to 
the indicator method. 
DIVISION OF PHYSICAL AND INORGANIC CHEMISTRY 
H. P. Tausor, chairman 
S. L. BIGELow, secretary 
JAMES R. WitHRow: The Relative Densities of 
Sodium Amalgam and Mercury. 
R. B. Moore: The Formation of Helium from the 
Thorium Emanation. 
A. B. Davis, Ivy MinuER and R. B. Moore: Nip- 
ponium. 
H. H. Wruuarp: The Quantitative Separation of 
Lithium from Sodium and Potasswwm. 
Sodium and potassium may be separated from 
lithium by precipitation as silicofluoride in methyl 
aleohol solution. Ethyl alcohol and acetone cause 
a large amount of lithium to be precipitated with 
the sodium and potassium. To the solution, which 
should be very small in volume—not over 10 ¢.c.— 
is added a little hydrochloric acid, then hydrofluo- 
silicic acid, and 75 or 80 e¢.c. methyl alcohol. 
Several hours are required for complete precipita- 
tion. If the amount of lithium is large, the pre- 
cipitate must be dissolved and reprecipitated. It 
may be dried at 150°—180°. 
Lithium may be quantitatively precipitated from 
a neutral solution by means of tribasic tetra- 
methyl-ammonium phosphate, methyl alcohol being 
added to make the precipitation more complete. 
If present in considerable amount, a little sodium 
is carried down, but a second precipitation will 
give a complete separation. 
H. H. Winuarp: Lhe Preparation of Perchloric 
Acid. 
Ammonium perchlorate is oxidized by means of 
nitrohydrochlorie acid, the ammonium being thus 
1 Jour. of the Am. Chem. Soc., 33, p. 711, 1911. 
2 Jour. of Ind. and Eng. Chem., 3, p. 559, 1911. 
