"(a) Except as hereinafter provided there shall be levied and collected on all distilled spirits and manufactured liquors manufactured in the Philippine Islands for domestic sale or consumption a tax of seventy centavos on each liter of proof spirits: Provided, That on all distilled spirits and manufactured liquors produced by the fermentation of sap from the nipa, coconut, or buri palm; juice, sirup, or sugar of the cane, there shall be levied and collected a tax of twenty-five centavos per proof liter: And Provided Further, That for the purposes of this article the term 'manufactured liquors' shall include liquid medicinal and toilet preparations, flavoring extracts, and all other preparation, of which, excluding the water, distilled spirits form the chief ingredient. The tax imposed by this section shall be paid by the distillery owners or persons having possession of such spirits before removal from the distillery or bonded warehouse, and the tax shall be collected on the whole number of proof liters and shall be increased in proportion for any greater strength than the strength of proof spirit as defined in this article, and every fractional part of a liter, amounting to a half liter or over in a cask or package, shall be taxed as a liter, and any fractional part of a liter less than a half in a cask or package shall be exempted from tax: Provided, That any package of spirits the total contents of which are less than a liter shall be taxed as one liter." �