What those alterations must be, it would now be premature to decide. The experience of Aberdeen might seem to suggest, that the system of constant supply (on all other accounts so eminently desirable for the metropolis) would in itself, if accompanied by the total disuse and prohibition of leaden cisternage, give sufficient security against the danger in question; or, on the other hand, further inquiry may show it to be quite indispensable for a safe distribution of the new supply, that leaden pipage should be entirely superseded by the use of some non-metallic material, as earthenware or glass. Should this change become necessary, its adoption would no doubt be facilitated by the comparative cheapness of these preferable materials. _Offensive or injurious Trades._ With respect to offensive or injurious trades and occupations pursued within the City of London, you were reminded by your Committee of Health, in their Report of March 26th, ‘that upon your attempting to put in force the powers of your Act of Parliament in reference thereto, it was found that considerable difficulties were opposed to your efforts. Sufficient powers (the Report proceeds to say) are not given by the City of London Sewers Act to meet some of the cases alluded to, while other legal and technical objections presented themselves to the enforcement of the powers in question.’ The Committee concluded their Report by ‘pointing out to you the necessity, when the question of renewing your Act should come into consideration, of procuring additional powers which may enable you effectually to remedy those evils.’ On the grounds thus expressed by your Committee, I avail myself of the present opportunity for bringing the subject again under your notice. In my former Report I spoke particularly of those trades and occupations which deal with animal substances liable to decomposition; and in expressing my knowledge of their danger to the health of an urban population, I argued that no occupation which ordinarily leaves a putrid refuse, nor any which consists in the conversion or manufacture of putrescent material, ought, under any circumstances, to be tolerated within a town. To that subject I now revert, only to assure your Hon. Court that the past year has given me no reason to alter my opinion. But the trades to which I wish, on this occasion, more especially to request your attention, are those which are complained of on the ground of their offensiveness, rather than of their injury to health--as nuisances rather than as poisons. During the year, I have received a very considerable number of complaints of this nature; some of them perhaps frivolous, but many well-founded and reasonable.