Special Orders, Numbers 21, under date of January 26, 1863, from Adjutant and Inspector General's Office, Richmond, and extended as far as Mandeville, La., by orders from these headquarters:

East of Pearl River trade with the enemy has been suppressed by their own action-the difficulty of passing Fort Pike with smuggled goods rendering their regulations effective, and the poverty of the inhabitants along the shore offering no strong inducements for the attempt. The fishing and oyster boats that once in awhile bring in a few pounds of coffee, &c., do not amount to enough to be called a trade, and may be disregarded as insignificant.

This whole coast is destitute and poverty-stricken in the extreme. Depending before the war upon an export trade of lumber, pine wood, and charcoal, their entire supplies were furnished by new Orleans, down to the very hay and winter provender for their cattle. Now that they are cut off from this resource, they have neither the requisite preparations nor the soil to raise provisions enough to support themselves.

In the two counties of Hancock and Harrison the most intelligent inhabitants calculate that with this favorable season not more than one-third enough corn has been grown to support the population.

From Mississippi City to Shieldsborough, prices at this time range from $7.50 to $15 per bushel for corn. Should the major-general commanding desire to maintain a force in these counties, I would suggest the advisability of establishing, during the season of good roads, two or more depots at such a distance from the shore as to be secure against surprise from the enemy, to which supplies floated down the Pearl and Pascagoula Rivers could now be hauled, and from which daily scouting parties could visit the prominent points and effectually perform the police duty of the coast.

As the enemy has shown very little disposition to land during the past season, and there is in fact nothing for them to steal, an efficient line of couriers, picked for their intelligence as well as other qualities, aiding a small cavalry force, might be sufficient for a time.

West of Pearl River, the trade with the enemy is carried on to a very considerable extent. It may be divided into three classes:

First. The blockade-running (so called), carried on by professed Confederates in skiffs and small sail-boats, starting from the marshes back of New Orleans, and rowing or sailing over, during the night, to mandeville, Lewisburg, Madisonville, &c., distances of 23 or 25 miles, and bringing shoes, clothing, provisions, salt, &c., which is sold for "city money," and mostly finds its way to Mobile.

This trade is injurious principally from its effect on our currency, which it depreciates as far back as 50 miles in the interior. The rate of exchange is about 5 for 1, but fluctuates with the New Orleans market.

The enemy are anxious to suppress this trade, and some fifteen boats were lately seized by them.

Second. The trade in lumber, fire wood, bricks, &c., which is regularly carried on. Nominally only inch boards and fire-wood are permitted, but, from the best information I can gather, most schooners smuggle on board a few bales of cotton, while from some of the outlying mills lumber fit for the repair and construction of gunboats has gone. From Bayou Bonfouca a schooner has run pretty regularly with bricks.

This trade has grown up from a quasi permission granted by the military authorities on account of the utter destitution of the inhabitants. If fails, however, to effect even the temporary relief contemplated, as the Federal authorities refuse to permit any supplies to be sent back,