The almost exclusively employed solution of sal ammoniac (ammonium chloride) presents the drawback that the zinc rods, glasses, etc., after a short use, become covered with a fine, yellow, very difficultly soluble, basic zinc salt, whereby the generation of the electric current is impaired, and finally arrested altogether. This evil may be remedied by an admixture of cane sugar. For a battery of ordinary size about 20 to 25 grams of sugar, dissolved in warm water, is sufficient per 50 to 60 grams of sal ammoniac. After prolonged use only large crystals (of a zinc saccharate) form, which, however, become attached only to the zinc rod in a few places, having very little disadvantageous effect upon the action of the batteries and being easy to remove, owing to their ready solubility.

<1>Bay Rum

I

Oil of bay....... 1 drachm

Alcohol......... 18 ounces

Water.......... 18 ounces

Mix and filter through magnesia.

II

Bay-leaf otto........ 0.5 ounce

Magnesium carbonate, 0.5 jounce

Jamaica rum........ 2 pints

Alcohol............. 3 pints

Water..............3 pints

Triturate the otto with the magnesium carbonate, gradually adding the other ingredients, previously mixed, and filter. If the rum employed contains sufficient sugar or mucilaginous matter to cause any stickiness to be felt on the skin, rectification will be necessary.