18 BULLETIN 524, U. S. DEPARTMENT OF AGRICULTURE. 
Analyses made by the water laboratory of the Bureau of Chem- 
istry of samples of salt collected from representative markets of 
the United States showed but very small percentages of calcium 
chlorid, magnesium chlorid, or sodium sulphate, the main impurity 
being calcium sulphate. However, within a radius of 200 miles 
from Cincinnati, a salt is produced and consumed largely locally 
that contains no sulphate and relatively large percentages of cal- 
cium and magnesium chlorids (CaCl 2 , 0.9 to 2.3 per cent; MgCl 2 , 
0.3 to 0.8 per cent). Table 14 shows that the effect of adding this 
salt to butter is to increase greatly the percentage of calcium oxid 
in the salt-free ash. An unneutralized butter might, therefore, 
occasionally be classed as neutralized if highly salted with salt con- 
taminated with considerable calcium chlorid. Analyses of butter, 
particularly if the butter is produced in the above locality, must be 
scrutinized with special care if they show no sulphate. Magnesium 
chlorid is associated with calcium chlorid in Ohio salt, and an 
increase in the magnesium oxid percentage in butter salted with it 
might be expected. Leach x states that the magnesium oxid content 
of the ash of milk is only 2.42 per cent. The maximum amount of 
magnesium oxid that could be present in 50 grams of butter, there- 
fore, would be only about 2 milligrams. Any increase could be 
regarded as due to impurities in the salt, and a high percentage 
of calcium oxid in the salt-free ash would thus be explained. How- 
ever, this salt is to be found only in a very limited area, and the 
amount of butter affected thereby is exceedingly small compared 
with the total product of the United States. The effect of calcium* 
chlorid, therefore, may be considered practically negligible except in 
a very few special cases. 
CALCIUM SULPHATE AND CALCIUM CHLORID. 
If both calcium sulphate and calcium chlorid are present, their 
effect is cumulative. In Table 14 is shown a case where about 5 per 
cent of salt which contained the maximum amount of calcium sul- 
phate and calcium chlorid allowed in dairy salts 2 was used in salting 
the butter. The percentage of calcium oxid in the salt-free ash 
reached 30, but when the effect of the calcium sulphate was calculated, 
though retaining the effect of the calcium chlorid, it dropped to 24, 
1 per cent below the maximum. When 2.5 per cent of this salt of 
maximum allowed impurity was employed, the percentage of calcium 
oxid in the salt-free ash was only 25, without any correction for 
calcium sulphate. 
MAGNESIUM CHLORID. 
Should salt containing magnesium chlorid be used the percentage 
of calcium oxid in the salt-free ash of the butter would be lowered 
1 Leach, Albert E., Food Inspection and Analysis, 3d,ed., p. 128, New York, 1913. 
2 U. S. Dept. of Agriculture, Office of the Secretary, Circ. 19, Standards of Purity for 
Food Products, p. 19. 
