The place was suffused with odd sounds, mostly the seething and hissing of diverse fuels burning in the furnaces, and the endless popping and ticking of the wooden wall panels. Another sound, faint and furtive, had reached Daniel's ears from time to time, but that surly porter who bestrides the gate of the conscious mind, spurning most of what is brought in by the senses and admitting only perceptions of Import or Quality, had construed this as a mouse sapping and mining the wall, and shouldered it aside. Now, though, it did come to Daniel's notice, for it grew louder: more rat than mouse. Isaac's tangents paper was in his hand, but he stood still for a few moments, trying to work out where this rat was busy, so that he could come back in daylight and investigate. The sound was resonating in a partition separating this room from the big laboratory with the furnaces, which was not of regular shape, but had several pop-outs and alcoves, built, by men who'd long since passed away, for heaven only knew what reasons: perhaps to encase a chimney here, or add a bit of pantry space there. Daniel had a good idea of what lay on the opposite side of that wall that was making the grinding noises: it was a little sideboard, set into an alcove in the corner of the laboratory, probably used once by servants when that room had been a dining-hall. Nowadays, Isaac used the cabinets below it to store Alchemical supplies. The counter was stocked with mortars, pestles, &c. For certain of the things Isaac worked with had a marked yearning to burst into flame, and so he was at pains to store them in that particular alcove, as far as possible from the furnaces.