10 BULLETIN 466, U. S. DEPARTMENT OF AGRICULTURE. 
standing for the basic solution and 0.79 for the normal lead, indicate 
what may happen when the basicity of the acetate is changed. 
Browne has called attention to the fact that the basicity of the lead 
acetate affects the polarization and also that by digestion of varying 
amounts of neutral lead acetate and litharge at least three well-defined 
subacetates may be prepared.’ Changes in treatment as to tempera- 
ture and length of time of heating and also quantity of the two ingre- 
dients may form any one of these or a mixture of two. 
An attempt was made to prepare solutions of these different basic 
lead acetates by varying the amount of lead oxid and the manner of 
solution as shown in Table VII. After the solutions were made up 
they were diluted to the same Brix as Winton’s solution and a layer 
of heavy oil placed on top. The alkalinity and amount of lead 
were determined in each. 
TaBLe VII.—Effect of method of preparation on basicity of lead acetate solution. 
Solu- Lead : 7. : Brix Nitric 
aaniiallincetate: Litharge.| Water. Solution treatment. reading. ride Lead. 
Ce N/10 
acid per Grams per 
Grams. | Grams. Ce: Degrees. 10 ce. | Percent.} 2.5 ce. 
jae eee 37 3 22.3 330 | Stooda week; shaken. 15. 60 30.15 5.7 0. 1426 
Desens or 44.6 330: |ss0lution=- lost. ...2:5222.:}_. sce Soe ee oo eee 
DIP 5.8 22.3 330 | Stood a week; shaken. 15.80 ISLES 5.59 . 1398 
Ae Hound s dry lead subacetate dissolved. 15.60 26.25 5. 82 . 1454 
ee PS 43.0 13.0 1,000 Bored. half hour...... 16. 20 26.00 5. 68 . 1421 
Gees 37.9 22.3 ” 330 S45 n de Se esocase 155070 27. 50 5.80 . 1449 
The pe 75.8 22.3 330 De ES ee eee 15. 87 19.60 5.73 . 1433 
Sutbeee Neutral lead et panes solution. 15. 87 2.00 5. 44 1359 
The lead numbers of six samples of maple sirup were determined, 
using these seven solutions. The results appear in Table VIII. 
TasLe VIII.—E£ ffect of basicity of lead acetate solutions upon the lead number. 
Lead solution number. 
Sample No. | 
1 | 3 4 | 5 6 7 8 
| oa a} dns Sl) te soll Ea eae 
hell at a eel mela lt Nia A ai a een 1.49] 1.13] 1.29] 131] 1.40] 133 0.29 
PRS Ait Uy Sees Fasth 1.74] 1.34] 1.42] 151] 1.62] 1.27 36 
3. LLL See te 1.70) 144 Io 157, |, 0 dG evo eed 9 -36 
ri COS Ea al ad alana Se 160°) 29) 8 1.37) ag ree ae ae 134 
a in ae ah ee Pe ae re 2.00} 1.47| 1.64] 1.70] 1.80| 1.41 .39 
GaN ra En eee ee ee eT" 1.865] 1.40| 1.58] ©63| £781 147 .37 
Awermpe esis ied oie: er £ 1.75) 1.34] 1.48] 1.53] 1.64| 1.32 | 35 
| 
Solution 4, the one usually employed, consisted of 3 parts of lead 
acetate to 2 parts of lead oxid. Solution 5 was carefully prepared 
by a method that should give this acetate. The results obtained 
from solutions 4 and 5 agree fairly well, the difference between the 
averages being only 0.05. Solutions 1 and 6 give results that are 
1U-S. Dept. Agr., Bur. Chem. Bul. 122, p. 223. 
