Page:Vol 6 History of Mexico by H H Bancroft.djvu/528

508 of such instability were the repeated frauds against the treasury by the clandestine exportations of precious metals, and the derangement of the mining business.

After the promulgation of the constitution of 1857, which did not confer on the general government power to legislate on mining, only two states, Hidalgo and Durango, framed a special mining code. The others merely adopted isolated measures. Oajaca, in 1873, declared free of taxation all capital exclusively invested in mining, on the mines and reduction-works, metals taken out in any form, upon their transit through the interior, or on their exportation, machinery, quicksilver, iron, blasting-powder, dynamite, and everything else for conducting the industry. Men engaged in mining were likewise exempted from military and municipal service. Puebla, between 1880 and 1882, also enacted liberal laws for the promotion of this branch of business. In most of the states, however, it was heavily burdened. The national constitution being amended in December 1883, the general government obtained power to issue a mining code for the whole republic.