The well-known faint odour of blood always pervades an establishment of this kind, and is especially marked in the drying chamber; but it does not pass beyond it in any such way as to cause a nuisance, unless the manufactory be very badly conducted. The two ordinary sources of nuisance from blood-albumen works consist: - (1) In the effluvia of putrid blood arising from the exhausted clots retained on the premises prior to removal. (2) In the general disagreeable faint smell proceeding from the yard and premises, especially when due cleanliness is not observed. (3) In effluvia from other and furthex processes, such as blood-boiling or blood-manure making, carried on upon the premises. As to the remedies for nuisances, Dr. Ballard observes: (1) It is a practice in some works to throw the exhausted clot into a clot-bin, where it is left until removal. But now, in the best works, the clots are at once put into moderately sized casks, through a sufficiently large opening at one end, which, when the cask is full, is closely fastened down with a cover secured by screws. (2) Such works as these require to be conducted in a very cleanly manner.

The yard should be well paved with stone, set so that no water may lodge upon it, and so that any offensive liquids that may reach it may not form pools, but flow readily away to the drain inlet. It should be kept at all times well swept up, and should be daily washed down with water. The separation room and the room in which the clots are sliced, when very near inhabited houses, should be closed in on all sides and ventilated at the roof, as recommended for slaughterhouses, and they should be well and evenly paved. The best kind of pavement for such a room is one of cement. Flagstones are apt to crack or loosen, and the pavement to become uneven, and thus liable to retain pools of liquid matters, or to the insinuation of these liquids between and beneath the stones. Nothing can be more objectionable than a wooden floor. The floors should be frequently scrubbed and cleaned, all the vessels and implements used ought to be regularly cleansed, and the whole interior of the buildings periodically lime-whited. The vapours from the drying chambers should be discharged at an elevation greater than that of adjoining houses.

A. H. Allen states that the qualities of blood-albumen as made by the leading firms are "refined," "prime," "No. 1," " No. 2," and " black." "Refined " is made from highly rectified serum, and is of a dirty-yellow colour; like "prime," it is employed as a mordant for printing delicate colours. "No. 1 " is darker-coloured and of less value, though suitable for all ordinary printing purposes. "No. 2 " is made from the second drainings of the serum, which, after the clear top serum has been siphoned off is more or less tinged with red, and consequently only fit for printing dark colours; as a rule, it also contains some insoluble matter, which is objectionable. " Black albumen " or dried blood is obtained from the last portions of serum, and is almost black in colour. It is not used in calico-printing, but finds applications in sugar refining, and Turkey red dyeing.

C. T. Kingzett has patented (No. 2630 of 1876) a process of bleaching blood-albumen, and at the same time preserving it from putrefaction, by aerial oxidation of certain hydro-carbons in the presence of the albuminous solution to be bleached at a temperature below the coagulable point. Thus, if turpentine be employed, peroxide of hydrogen is formed on the one hand (and this bleaches the albumen), while other substances are simultaneously produced in sufficient quantity to preserve the mass from putrefactive decomposition. During the past 4 years this process has been worked on serum and dark-coloured scales, producing solutions containing 2 to 4 lb. of albumen per gallon. The existence of the salts present in serum does not interfere with its photographic applications.

Kingzett also experimented in the direction of utilizing flesh, casein, etc, as a source of albumen. And Portheim has patented (No. 1686 of 1881) a process with the same object. The difficulty to be overcome is to retain the coagulability of the albumen, on which its value entirely depends.