Causes. Dry skin (xerosis) often has an environmental cause. Certain diseases also can significantly affect your skin. Potential causes of dry skin include: Weather. Skin tends to be driest in winter, when temperatures and humidity levels plummet. But the season may not matter as much if you live in desert regions. Heat.
Brownian movement. n. The random movement of microscopic particles suspended in a liquid or gas, caused by collisions with molecules of the surrounding medium.Also called Brownian motion, molecular movement, pedesis.he random movement of microscopic particles suspended in a liquid or gas, caused by collisions with molecules of the surrounding medium.
  Brownian motion is a random motion produced by the vibration of molecules by ambient heat energy. Motility is the ability to move spontaneously and independently using â¦ internal energy stores to effect the movement.