It will be observed that the letter of Lord John Russell, in accordance with the address of the House of Lords to Her Majesty, merely directed us to make inquiry as to the extent to which the causes of disease, stated in the Reports of Drs. Arnott and Kay, and of Dr. Southwood Smith, to prevail amongst the labouring classes of the metropolis, prevail also amongst the labouring classes in other parts of England and Wales, and to transmit the results of that inquiry to the Secretary of State for the Home Department. We should, therefore, have complied with the letter of our instructions if we had merely laid before you the information which we have collected in answer to the inquiries which we circulated. It appeared to us, however, that so large a mass of miscellaneous evidence would not be likely to convey a distinct view of the subject of inquiry if we presented it in an undigested form to Her Majesty’s Government; and we, therefore, requested our secretary, Mr. Chadwick, to peruse the information which we had received, (including the returns from the boards of guardians and union medical officers,) and, by comparing the different statements with such authentic facts bearing upon the question as he might collect from other sources, to frame a report which should exhibit the principal results of the inquiry which we were instructed to conduct. We subjoin the Report which Mr. Chadwick has prepared in accordance with this request; and we present to you this, and the other accompanying documents, in the full assurance that, as they contain matters seriously concerning the welfare of the community in general, and particularly of the working classes, they will receive the attentive consideration of Her Majesty’s Government. We have the honour to be, Sir, Your very faithful and obedient Servants GEORGE NICHOLLS, GEORGE CORNEWALL LEWIS, EDMUND WALKER HEAD. APPENDIX. 1.—_Circular Letter of Instructions to the Assistant Commissioners in England._ Poor Law Commission Office, Somerset House, 8th November, 1839. Sir,—I am directed by the Poor Law Commissioners to call your attention to the following letter lately addressed to them by Lord John Russell. Whitehall, August 21st, 1839.