809. Those who are not in health have impurities in the blood, and the skin is not in a healthy condition.—Testimonies for the Church 3:70. HL 191.2
810. The studied habit of shunning the air and avoiding exercise closes the pores,—the little mouths through which the body breathes,—making it impossible to throw off impurities through that channel. The burden of labor is thrown upon the liver, lungs, kidneys, etc., and these internal organs are compelled to do the work of the skin.—Testimonies for the Church 2:524. HL 191.3
811. These pores have become clogged and cannot perform the task allotted to them, and so the internal organs have a double task thrown upon them, and the whole system is deranged.—The Health Reformer, September 1, 1866. HL 191.4