An Etymological Dictionary of the German Language/Schlauch
Schlauch, m., ‘leather bag, bottle, or pipe, funnel,’ from MidHG. slûch, m., ‘skin, slough (of a snake), leather bag, pipe’; corresponding to E. slough, Swed. dial. slug. MidHG. slûch, ‘gullet, throat; gulf, abyss,’ is a different word; late OHG. slûch, m., ‘yawning chasm’ (allied to schlucken). ModHG. Schlund, as well as Lat. vorâgo, ‘abyss,’ allied to vorare, ‘to swallow up,’ shows a similar evolution in meaning; comp. Lat. faux, ‘gullet, throat, abyss.’