Arthur Latham Perry,
Principles of Political Economy
“ These terms are used more particularly in relation to Tariff-taxes, but there is nothing in the distinction itself so to limit its application. A Specific tax is a tax of so many cents or dollars on the pound, yard, gallon, or other quantity measurable: an Advalorem tax is a tax of so much per centum on the invoiced or appraised money value of the goods subject to the tax. Specific taxes, accordingly, are far simpler and steadier in their operation than the others ”
