Second only in importance to the closure of these side openings, is the provision that the internal facing of all the walls in the Slaughter-house should be of a non-absorbing nature, and I am still of the opinion, which I ventured to urge unsuccessfully when the Bye-laws were framed in November, 1874, viz., that the height mentioned in Bye-law VI. is insufficient for the purpose, and that the _whole wall-surface_ should be coated with a “hard, smooth, and impervious material,” such as is now used in the wards of our best Metropolitan hospitals. When this is done, the disgusting and blood-stained appearance, seen on the walls of these Slaughter-houses on your recent visit, will be impossible, and one fertile source of disease averted. I entertain a strong objection to the partitions in any part of the Slaughter-house, Pound, or Lair, being constructed of wood, for the reason that this material becomes rapidly sodden by the constant presence of hot moist air, in which state it must inevitably absorb noxious and other vapours, and soon become saturated with albuminoid organic matter, and afford a ready nidus for the development and propagation of any disease germs which may be floating in the air. The Butchers deny the existence of unpleasant odours in Slaughter-houses; but whilst freely admitting this to be a matter in which the senses of ordinary men may be differently affected to those of persons constantly living in and enjoying an atmosphere, however nauseous, I must insist that the air within a Slaughter-house can never be wholesome so long as the disgusting practice of opening the paunches of hot, reeking animals, directly after they are knocked down, is allowed to continue. From the nature of the food eaten by ruminants, and during its disintegration and assimilation, enormous quantities of stinking volatile gases are formed, and the sudden disengaging of these when the intestines are ripped up and emptied, before being handed over to the tripe-dresser, must always fill the surrounding air with what common mortals would consider vile and poisonous smells. You may remember I urged you to make a Bye-law prohibiting this custom, and I regret the more it was overruled in Committee, since the only excuse offered for its continuance was the very inadequate plea that the guts of a large animal were too heavy and bulky to be removed without being first deprived of their contents. Mr. Simon, C.B., F.R.S., &c., &c., my talented predecessor, insisted in the Blue Book before referred to, that “an atmosphere which smells of organic decomposition, is an unwholesome atmosphere; that it at least favours the spread, perhaps also what may virtually be considered the production, of morbid infections.”