243. Other Deceptions. Nearly all patent medicines contain some alcohol, and in many, the quantity of alcohol is far in excess of that found in the strongest wines. Tonics and bitters advertised as a cure for spring fever and a worn-out system are scarcely more than cheap cocktails, as one writer has derisively called them, and the amount of alcohol in some widely advertised patent remedies is alarmingly large and almost equal to that of strong whisky. [Illustration: FIG. 161.--Diagram showing the amount of alcohol in some alcoholic drinks and in one much used patent medicine.] Some conscientious persons who would not touch beer, wine, whisky, or any other intoxicating drink consume patent remedies containing large quantities of alcohol and thus unintentionally expose themselves to mental and physical danger. In all cases of bodily disorder, the only safe course is to consult a physician who has devoted himself to the study of the body and the methods by which a disordered system may be restored to health. CHAPTER XXVI NITROGEN AND ITS RELATION TO PLANTS 244. Nitrogen. A substance which plays an important part in animal and plant life is nitrogen. Soil and the fertilizers which enrich it, the plants which grow on it, and the animals which feed on these, all contain nitrogen or nitrogenous compounds. The atmosphere, which we ordinarily think of as a storehouse of oxygen, contains far more nitrogen than oxygen, since four fifths of its whole weight is made up of this element. Nitrogen is colorless, odorless, and tasteless. Air is composed chiefly of oxygen and nitrogen; if, therefore, the oxygen in a vessel filled with air can be made to unite with some other substance or can be removed, there will be a residue of nitrogen. This can be done by floating on water a light dish containing phosphorus, then igniting the phosphorus, and placing an inverted jar over the burning substance. The phosphorus in burning unites with the oxygen of the air and hence the gas that remains in the jar is chiefly nitrogen. It has the characteristics mentioned above and, in addition, does not combine readily with other substances. 245. Plant Food. Food is the course of energy in every living thing and is essential to both animal and plant life. Plants get their food from the lifeless matter which exists in the air and in the soil; while animals get their food from plants. It is true that man and many other animals eat fleshy foods and depend upon them for partial sustenance, but the ultimate source of all animal food is plant life, since meat-producing animals live upon plant growth. Plants get their food from the air, the soil, and moisture. From the air, the leaves take carbon dioxide and water and transform them into starchy food; from the soil, the roots take water rich in mineral matters dissolved from the soil. From the substances thus gathered, the plant lives and builds up its structure.