The secession of South Carolina from the Confederacy excites more condemnation now than it did when it first occurred. Since then business has decreased considerably among the merchants; orders to manufacturers are very limited; thousands of mechanics and clerks are thrown out of employment, all of whom see, in the action of the Palmetto State, the proximate cause of these disasters, and they look not beyond. Conservatives assert that South Carolina has always been a troublesome State; Democrats that she acted too precipitately; Republicans that secession is treason, which LINCOLN, like ANDREW JACKSON, will put down, as he did nullification; while a portion of the press and political philosophers declare, with great gravity, that the success of the sectional candidates for the Presidency, and the consequences resulting therefrom, are all owing to the convictions of the 'Northern conscience.'

The highest law of conscience known, is 'to do unto others as you would that they should do unto you.' Now, in order to discover whether the 'Northern conscience' acts in accordance with this rule, it would seem fair to apply the tests of its past history in order to analyse it. A retrospect over the last thirty five years presents to view the fact that the constant dictate and effort of the 'Northern conscience was, has been, and is still, to have the whole Confederacy taxed and to pay tribute for the support of Northern manufactures, by protective tariff laws, coasting navigation acts, bounties and drawbacks. Next in the retrospect comes the crusade of the 'Northern conscience' against negro slavery in the Southern States. Now this 'Northern conscience' will touch, taste, handle and wear those unclean things, the products of slave labor, sugar, rice, coffee, cotton and tobacco. Although the most effective mode and peaceful way of terminating negro slavery would be the non consumption of the products of slave labor, which must take place when Abolition triumphs, inasmuch as those products of negro slave labor are not produced by free negro labor in Hayti, Jamaica or any where else. But the 'Northern conscience' must have coffee from Brazil, and sugar to sweeten it from Cuba. It must have cotton from the southern States to manufacture, to wear, and to traffic in. It must have tobacco to smoke in segars and to chew in quids. In short, there never was a more shameless hypocritical conscience than the 'Northern conscience.'

The Abolition conscience of England contributed one hundred millions of dollars to the slave proprietors of her West India Islands when she committed that great folly in her history - the abolition of negro slavery; but the 'Northern conscience' makes no sacrifices - it only demands other to do so - i.e. that the Southern States shall give up slave property amounting to four thousand millions of dollars, according to Senator BENJAMIN'S estimate, to please those divine teachers of the negro gospel dispensation, BEECHER, CHEEVER, SUMNER & CO. It might be proper, as indeed it would be conscientiously equitable, to require the 'Northern conscience' to pay half this amount, say two thousand millions of dollars to the Southern States on the condition of abolishing slavery. There are, in the eighteen free States, 141 Congressional districts. Divide two thousand millions of dollars by 141, exhibits a quotient of fourteen millions one hundred and eighty four thousand three hundred and ninety seven dollars, to be contributed by each Congressional district, which, multiplied by eleven, the number of districts in Massachusetts, would amount to one hundred and fifty six millions twenty eight thousand three hundred and sixty seven dollars to be paid by the 'Northern conscience' of the great school of Massachusetts to effect the abolition of slavery.

But the 'Northern conscience' of the Massachusetts school is too transcendental to be governed by any law of holy writ or social equity. There is, however, one higher law, and but one, that will make this conscience pause in its over-weening career, and that one is: 'Will it pay?'

BEECHER, CHEEVER & CO., make, it is alleged, 'pence and popularity' by their Abolitionism. A benevolent society of this city, that expends over six thousand dollars annually on charitable objects, got up a course of lectures two years ago, free to mechanics and tradesmen, and employed a number of clergymen as lecturers; BEECHER charged them two hundred dollars for his lecture, Drs. BETHUNE and ADAMS one hundred dollars, and some others only fifty dollars per lecture. The gratuitous lectures were by laymen.

The Abolitionists' 'Northern conscience' is decidedly in favor of what is called 'free labor,' which is the greatest falsity of modern times. In England it is the 'maximum of production on the minimum of subsistence.' In the State of New York, thirty years ago, it was called by working men 'wages slavery, or the freedom of working for such wages as you can get, or starve.' It is a bed of Procrustes on which all mechanics of the same trade are compelled to take the same rate of wages or get no work; the operatives having no freedom whatever in naming the price of their labor. About twenty five years ago the journeymen tailors of New York made a strike 'in resistance to a reduction of the prices on their labor,' for which they were prosecuted and tried before Judge SAVAGE, who pronounced them guilty of a 'conspiracy against trade and commerce.' Recently, there was a general 'strike' in Massachusetts by the shoemakers to obtain a higher rate than fifteen cents per pair for making shoes, alleging that they had to work eighteen hours a day to earn four dollars and a half per week. But the 'Northern conscience' disregarded the voice of these free laborers - its philanthropy is wholly towards negros - so that all that is left is misanthropy towards white people.

It is both a falsity and a fraud to call the labor system of England and the free States 'free labor.' It may suit the nature and capacities of white people, but is by no means suitable to the nature and capacities of the negro. Persons who say it is suitable to the latter, not only prove their ignorance of natural facts, but their lack of common sense. YOURS, &c.