Strangers are permitted to visit the jail on Thursday, when MRS. FRY reads and explains passages of the Bible to the prisoners. Her voice is extremely fascinating; its pure, clear tones are admirably calculated to plead the cause of virtue and humanity. The late queen expressed a wish to see MRS. FRY, and in the most flattering terms testified the admiration she felt for her conduct. The thanks of the city of London were voted to her; and, in short, there is not an Englishman who does not bless her name." How worthy of all admiration is such conduct in a female! But if the principle which DR. CHALMERS has stated with so much beauty and force, and which has been so fully and delightfully exemplified by the seraphic spirits of a HOWARD and a FRY, is correct, how humbling to the christian community are the inferences which follow. Why are our prisons such scenes of cruelty and such schools of crime? Because christian churches and christian individuals are destitute of the practical good will, and the expansive benevolence of the gospel of Christ. When christians begin to _act_ on the principles of their profession, prisons will begin to grow pure; and when all christians fully perform their solemn duties to the erring and the wretched, prison walls and prison vices will be no more. In a purified society they cannot exist; and the degraded condition of the prisoners in our country, and the rapid increase of their numbers, are sure indications of the want of piety and godliness in the land. I might spin out remarks to an indefinite length, but it would be to no useful purpose. I can weep over the evils which I am unable to cure. I do not expect any great improvement _in_ our prisons, till I see great reformations _out_ of them. From the society of the free all our prisoners are taken, and till that society is purified it will continue to furnish its annual victims to the penitentiary; but when that is done, the fetters and dungeons of the captive will crumble to dust, and the improvement of prisoners will be simultaneous with the reformation of the free. These two classes act and react upon each other, and they must ultimately wear the same moral complexion. If vice is to triumph over virtue, then all will be just fit for a dungeon; but if virtue is to become universal, then will the bond and the free be equal sharers in the bliss. But as the prey _is_ to be taken from the mighty, and as all flesh _is_ to see the salvation of the Lord, I am sure that "in the dispensation of the fulness of times," the vices and crimes of prisoners will cease, and the voice of the oppressors be heard no more. REV. JOHN ROBBINS' VISIT TO WINDSOR PRISON.