Labels separate from tin because the paste becomes too dry. Some moisture is presumably always present; but more is required to cause continued adhesion in the case of tin than where the container is of

glass. Paste may be kept moist by the addition of calcium chloride, which is strongly hygroscopic, or of glycerine.

The following formulas for pastes of the type indicated were proposed by Leo Eliel:

I

Tragacanth........ 1 ounce

Acacia............. 4 ounces

Thymol...........   14 grains

Glycerine.......... 4 ounces

Water, sufficient to

make............ 2 pints

Dissolve the gums in 1 pint of water, strain, and add the glycerine, in which the thymol is suspended; shake well and add sufficient water to make 2 pints. This separates on standing, but a single shake mixes it sufficiently for use.

II

Rye flour..........     8 ounces

Powdered acacia. ...     1 ounce

Glycerine..........     2 ounces

Oil of cloves........   40 drops

Rub the rye flour and acacia to a smooth paste with 8 ounces of cold water; strain through cheese cloth, and pour into 1 pint of boiling water, and continue the heat until as thick as desired. When nearly cold add the glycerine and oil of cloves.

III

Rye flour.......... 5 parts

Venice turpentine. . . 1 part Liquid glue, a sufficient quantity

Rub up the flour with the turpentine and then add sufficient freshly prepared glue (glue or gelatine dissolved in water) to make a stiff paste. This paste dries slowly.

IV

Dextrine...........     2 parts

Acetic acid.........     1 part

Water.............     5 parts

Alcohol, 95 per cent .     1 part

Dissolve the dextrine and acetic acid in water by heating together in the water bath, and to the solution add the alcohol.

V

Dextrine........... 3 pounds

Borax............. 2 ounces

Glucose........... 5 drachms

Water...........3 pints 2 ounces

Dissolve the borax in the water by warming, then add the dextrine and glucose, and continue to heat gently until dissolved.

Another variety is made by dissolving a cheap Ghatti gum in limewater, but it keeps badly.

VI

Add tartaric acid to thick flour paste. The paste is to be boiled until quite thick, and the acid, previously dissolved in a little water, is added, the proportion being about 2 ounces to the pint of paste.