The resulting compounds of which methyl nitrate (CH_{3}NO_{3}) may be taken as the type belong to the class known as _ethereal salts_, the name having been given them because some of them possess pleasant ethereal odors. It will be seen that the ethereal salts differ from ordinary salts in that they contain a hydrocarbon radical, such as CH_{3}, C_{2}H_{5}, C_{3}H_{5}, in place of a metal. ~The nitrates of glycerin~ (_nitroglycerin_). Nitric acid reacts with glycerin in the same way that it reacts with a base containing three hydroxyl groups such as Fe(OH)_{3}: Fe(OH)_{3} + 3HNO_{3} = Fe(NO_{3})_{3} + 3H_{2}O, C_{3}H_{5}(OH)_{3} + 3HNO_{3} = C_{3}H_{5}(NO_{3})_{3} + 3H_{2}O. The resulting nitrate (C_{3}H_{5}(NO_{3})_{3}) is the main constituent of _nitroglycerin_, a slightly yellowish oil characterized by its explosive properties. Dynamite consists of porous earth which has absorbed nitroglycerin, and its strength depends on the amount present. It is used much more largely than nitroglycerin itself, since it does not explode so readily by concussion and hence can be transported with safety. ~The fats.~ These are largely mixtures of the ethereal salts known respectively as olein, palmitin, and stearin. These salts may be regarded as derived from oleic, palmitic, and stearic acids respectively, by replacing the hydrogen of the acid with the glycerin radical C_{3}H_{5}. Since this radical is trivalent and oleic, palmitic, and stearic acids contain only one replaceable hydrogen atom to the molecule, it is evident that three molecules of each acid must enter into each molecule of the ethereal salt. The formulas for the acids and the ethereal salts derived from each are as follows: HC_{18}H_{33}O_{2} (oleic acid) C_{8}H_{6}(C_{18}H_{33}O_{2})_{3}, (olein) HC_{16}H_{31}O_{2} (palmitic acid) C_{3}H_{5}(C_{16}H_{31}0_{2})_{3} (palmitin) HC_{18}H_{35}O_{2} (stearic acid) C_{3}H_{5}(C_{18}H_{35}O_{2})_{3} (stearin) Olein is a liquid and is the main constituent of liquid fats. Palmitin and stearin are solids. ~Butter fat and oleomargarine.~ Butter fat consists principally of olein, palmitin, and stearin. The flavor of the fat is due to the presence of a small amount of butyrin, which is an ethereal salt of butyric acid. Oleomargarine differs from butter mainly in the fact that a smaller amount of butyrin is present. It is made from the fats obtained from cattle and hogs. This fat is churned up with milk, or a small amount of butter is added, in order to furnish sufficient butyrin to impart the butter flavor. ~Saponification.~ When an ethereal salt is heated with an alkali a reaction expressed by the following equation takes place: C_{2}H_{5}NO_{3} + KOH = C_{2}H_{5}OH + KNO_{3}.