This familiar liquid requires no description, but it may not be out of place to caution our readers that failure in the making of varnishes, etc., very often arises from the use of alcohol which by standing has lost its strength. Ordinary alcohol is a mixture of alcohol and water, and as the alcohol evaporates more readily than the water, when the mixture is allowed to stand for any length of time it becomes reduced in strength, that is to say the proportion of alcohol becomes less and that of the water more.