Alcohol unites more easily with oxygen than most other food materials, hence it takes away oxygen that would otherwise be used in oxidizing these foods. Imperfect oxidation of foods causes the development and retention of poisons in the blood which it becomes the work of the kidneys to remove. If the kidneys become overworked, disease will occur. Such disease is likely to make itself felt as rheumatism or gout, both of which are believed to be due to waste products (poisons) in the blood. Poisons produced by Alcohol.--When too little oxygen enters the draft of the stove, the wood is burned imperfectly, and there are clouds of smoke and irritating gases. So, if oxygen unites with the alcohol and too little reaches the cells, instead of carbon dioxide, water, and urea being formed, there are other products, some of which are exceedingly poisonous and which the kidneys handle with difficulty. The poisons retained in the circulation never fail to produce their poisonous effects, as shown by headaches, clouded brain, pain, and weakness of the body. The word "intoxication" means "in a state of poisoning." These poisons gradually accumulate as the alcohol takes oxygen from the cells. The worst effects come last, when the brain is too benumbed to judge fairly of their harm. REFERENCE BOOKS ELEMENTARY Hunter, _Laboratory Problems in Civic Biology_. American Book Company. Davison, _Human Body and Health_. American Book Company. Gulick, _Hygiene Series, Emergencies, Good Health_. Ginn and Company. Hough and Sedgwick, _The Human Mechanism_. Ginn and Company. Macy, _General Physiology_. American Book Company. Ritchie, _Human Physiology_. World Book Company. XXIII. BODY CONTROL AND HABIT FORMATION _Problems.--How is body control maintained? (a) What is the mechanism of direction and control? (b) What is the method of direction and control? (c) What are habits? How are they formed and how broken? (d) What are the organs of sense? What are their uses? (e) How does alcohol affect the nervous system?_ LABORATORY SUGGESTIONS _Demonstration._--Sensory motor reactions. _Demonstration._--Nervous system. Models and frog dissections. _Demonstration._--Neurones under compound microscope (optional). _Demonstration._--Reflex acts are unconscious acts: show how conscious acts may become habitual. _Home exercise_ in habit forming. _The senses.--Home exercises._--(1) To determine areas most sensitive to touch. (2) To determine or map out hot and cold spots on an area on the wrist. (3) To determine functions of different areas on tongue. _Demonstration._--Show how eye defects are tested. _Laboratory summary._--The effects of alcohol on the nervous system.