It is said that in northern Corea, “the men hunt the tigers during six months in the year, and the tigers hunt the men during the other six months.” In Mexico, along the coast, the northers rage during one half of the year, while the yellow fever reigns through the other half, maintaining the balance of power and an equilibrium of misery. Fire broke out on the _Mississippi_, owing to spontaneous combustion of impure coal put on board at Norfolk, in a wet condition. It was extinguished only by pumping water into the coal-bunkers. Through this necessity, the flag-ship, which had thus far defied the powers of air, sun and moisture, became a foothold of pestilence. Yellow fever broke out, and, towards the end of July, the _Mississippi_ had to be sent to Pensacola. Perry shifted his flag to the _Germantown_, (a fine old frigate fated to be burned at Norfolk in 1861), Capt. Buchanan, and sailed July 16, to inquire after the health of the men on blockade and garrison duty in the ports, while the two hundred or more patients of the _Mississippi_ quickly convalesced in Florida. Northers and vomito, though depended on by the Mexicans to fight in their courses against the Yankees, did not work together in the same time. The northers thus far had kept back the yellow fever, but now while Scott’s army moved in the salubrious highlands of the interior, the unacclimated sailors remaining on the pestilential coast were called to fight disease, insects, and banditti, at once. They must hold ports with pitifully small garrisons, enforcing financial regulations, and grappling with villainous consuls who desecrated their national flags by smuggling from Havana, and by harboring the goods of the enemy. Many so-called “consuls” in Mexican ports were never so accredited, and could not appreciate the liberal policy of the United States towards neutrals. While the plague was impending, there was a woeful lack of medical officers; one surgeon on seven ships at anchor, and two assistant surgeons in the hospital, composing the medical staff. The patients at Salmadina did well, but the fever broke out among the merchant vessels at Vera Cruz and the foreign men-of-war at Sacrificios. By the middle of August, the sickly season was well advanced, and with so many of the large ships sent home for the health of the men, Perry’s force was small enough, while yet the guerrillas were as lively and seemingly as numerous and ubiquitous as mosquitoes. Fortunately for the American cause, some of the most noted of the guerrilla chiefs fell out among themselves and came to blows. Perry wrote to Washington earnestly requesting that marines be sent out to act as flankers to parties of seamen landed to cut off guerrilla parties. In the night attacks which were frequent, the men and officers had to stand to their guns for long hours in drenching dews and heavy miasma.