The natural smell of leather has a tendency to scare domestic animals. To avoid this, an essential part of the manufacturing process is to stack the animal skins in layers alternating with layers of horse dung, roll them up, and store them in barrels for six months. What we think of as the smell of leather is actually the result of this process.
The 'frisbee' quality of biscuits is determined by the nature of the top surface. In scientific tests, smooth-topped Rich Tea scored the longest distance, and Lincoln showed the greatest lift, due to the vortices created by the regular pattern of knobbles on the top. Maryland Cookies will not fly.