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Determining the precise mechanisms underlying synaptic transmission and plasticity requires studying small populations of synapses, ideally single synapses. While some synapses are highly suited for study at this level, e.g., the Calyx of Held5, for most synaptic populations this is extremely difficult due to the small and diffuse nature of the synaptic connections. Two major electrophysiology techniques have been developed to examine single synaptic connections: The first is minimal stimulation, where one presynaptic fiber is presumed stimulated extracellularly. The second technique is paired recordings, where two simultaneous whole cell recordings from synaptically connected neurons is performed. A major advantage of minimal stimulation is that it is rapid and relatively simple to perform, involving placement of an extracellular stimulating electrode into the axonal tract while simultaneously recording from a postsynaptic neuron. The primary concern when using this technique is that reliable stimulation of a single cell can rarely be guaranteed trial after trial.
To this end, we all denied that we had been guilty of intended flight. Master Thomas said that the evidence he had of our intention to run away, was strong enough to hang us, in a case of murder. \"But,\" said I, \"the cases are not equal. If murder were committed, some one must have committed it--the thing is done! In our case, nothing has been done! We have not run away. Where is the evidence against us We were quietly at our work.\" I talked thus, with unusual freedom, to bring out the evidence against us, for we all wanted, above all things, to know the guilty wretch who had betrayed us, that we might have something tangible upon which to pour our execrations. From something which dropped, in the course of the talk, it appeared that there was but one witness against us--and that that witness could not be produced. Master Thomas would not tell us who his informant was; but we suspected, and suspected one person only. Several circumstances seemed to point SANDY out, as our betrayer. His entire knowledge of our plans--his participation in them--his withdrawal from us--his dream, and his simultaneous presentiment that we were betrayed--the taking us, and the leaving him--were calculated to turn suspicion toward him; and yet, we could not suspect him. We all loved him too well to think it possible that he could have betrayed us. So we rolled the guilt on other shoulders.
Now, although this movement did not extend to me, in form, it did reach me, in fact. The spirit which it awakened was one of malice and bitterness, toward colored people generally, and I suffered with the rest, and suffered severely. My fellow apprentices very soon began to feel it to be degrading to work with me. They began to put on high looks, and to talk contemptuously and maliciously of \"the niggers;\" saying, that \"they would take the country,\" that \"they ought to be killed.\" Encouraged by the cowardly workmen, who, knowing me to be a slave, made no issue with Mr. Gardiner about my being there, these young men did their utmost to make it impossible for me to stay. They seldom called me to do any thing, without coupling the call with a curse, and, Edward North, the biggest in every thing, rascality Page 313included, ventured to strike me, whereupon I picked him up, and threw him into the dock. Whenever any of them struck me, I struck back again, regardless of consequences. I could manage any of them singly; and, while I could keep them from combining, I succeeded very well. In the conflict which ended my stay at Mr. Gardiner's, I was beset by four of them at once--Ned North, Ned Hays, Bill Stewart, and Tom Humphreys. Two of them were as large as myself, and they came near killing me, in broad day light. The attack was made suddenly, and simultaneously. One came in front, armed with a brick; there was one at each side, and one behind, and they closed up around me. I was struck on all sides; and, while I was attending to those in front, I received a blow on my head, from behind, dealt with a heavy hand-spike. I was completely stunned by the blow, and fell, heavily, on the ground, among the timbers. Taking advantage of my fall, they rushed upon me, and began to pound me with their fists. I let them lay on, for a while, after I came to myself, with a view of gaining strength. They did me little damage, so far; but, finally, getting tired of that sport, I gave a sudden surge, and, despite their weight, I rose to my hands and knees. Just as I did this, one of their number (I know not which) planted a blow with his boot in my left eye, which, for a time, seemed to have burst my eyeball. When they saw my eye completely closed, my face covered with blood, and I staggering under the stunning blows they had given me, they left me. As soon as I gathered sufficient strength, I picked up the hand-spike, and, madly enough, attempted Page 314to pursue them; but here the carpenters interfered, and compelled me to give up my frenzied pursuit. It was impossible to stand against so many.
Behold the practical operation of this internal slave trade--the American slave trade sustained by American politics and American religion! Here you will see men and women reared like swine for the market. You know what is a swine-drover! I will show you Page 447a man-drover. They inhabit all our southern states. They perambulate the country, and crowd the highways of the nation with droves of human stock. You will see one of these human-flesh-jobbers, armed with pistol, whip, and bowie-knife, driving a company of a hundred men, women, and children, from the Potomac to the slave market at New Orleans. These wretched people are to be sold singly, or in lots, to suit purchasers. They are food for the cottonfield and the deadly sugar-mill. Mark the sad procession as it moves wearily along, and the inhuman wretch who drives them. Hear his savage yells and his blood-chilling oaths, as he hurries on his affrighted captives. There, see the old man, with locks thinned and gray. Cast one glance, if you please, upon that young mother, whose shoulders are bare to the scorching sun, her briny tears falling on the brow of the babe in her arms. See, too, that girl of thirteen, weeping, yes, weeping, as she thinks of the mother from whom she has been torn. The drove moves tardily. Heat and sorrow have nearly consumed their strength. Suddenly you hear a quick snap, like the discharge of a rifle; the fetters clank, and the chain rattles simultaneously; your ears are saluted with a scream that seems to have torn its way to the center of your soul. The crack you heard was the sound of the slave whip; the scream you heard was from the woman you saw with the babe. Her speed had faltered under the weight of her child and her chains; that gash on her shoulder tells her to move on. Follow this drove to New Orleans. Attend the auction; see men examined like horses; see the forms of women rudely and brutally exposed to the shocking gaze of American slave-buyers. See this drove sold and separated forever; and never forget the deep, sad sobs that arose from that scattered multitude. Tell me, citizens, where, under the sun, can you witness a spectacle more flendish and shocking. Yet this is but a glance at the American slave trade, as it exists at this moment, in the ruling part of the United States.
But here is a still more important fact, illustrating the designs of the slave power. It is a fact full of meaning, that no sooner did the democratic slavery party come into power, than a system of legislation was presented to the legislatures of the northern states, designed to put the states in harmony with the fugitive slave law, and the malignant bearing of the national government toward the colored inhabitants of the country. This whole movement on the part of the states, bears the evidence of having one origin, emanating from one head, and urged forward by one power. It was simultaneous, uniform, and general, and looked to one end. It was intended to put thorns under feet already bleeding; to crush a people already bowed down; to enslave a people already but half free; in a word, it was intended to discourage, dishearten, and drive the free colored people out of the country. In looking at the recent black law of Illinois, one is struck dumb with its enormity. It would seem that the men who enacted that law, had not only banished from their minds all sense of justice, but all sense of shame. It coolly proposes to sell the bodies and souls of the black to increase the intelligence and refinement of the whites; to rob every black stranger who ventures among them, to increase their literary fund. 59ce067264