Alkaloids are compounds of a vegetable origin, generally of complex composition and capable of producing marked effects upon animals. They all contain nitrogen. Explosives which are a chemical means of storing tremendous amounts of energy, are mostly of some nitrogenous compound. Albumen is an organic compound of great importance in life, which, besides being the characteristic ingredient in the white of an egg, abounds in the serum of the blood and forms an important part of the muscles and brain. Albuminoids play the most vital rôle in plant life and are an extensive class of organic bodies found in plants and animals, as they are found to form the chief constituents of blood, nerves. All albuminoids found in animals are produced by the processes fulfilled in plants. Their exact constitution is not known; analysis shows that they contain approximately: Carbon 50-55%, Hydrogen 6.9-7.5%, Nitrogen 15-19%, Oxygen 20-24%, Sulphur 0.3-2.0%. Venous blood contains in 100 volumes: Nitrogen, 13; Carbonic Acid, 71.6; Oxygen, 15.3. Arterial blood: Nitrogen, 14.5; Carbonic Acid, 62.3; Oxygen, 23.2. “Nitrogenous compounds in general, are extremely prone to decomposition; their decomposition often involving a sudden and great evolution of force. We see that substances classed as ferments ... are all nitrogenous ... and we see that even in organisms and parts of organisms where the activities are least, such changes as do take place are initiated by a substance containing nitrogen.... We see that organic matter is so constituted that small incidental actions are capable of initiating great reaction and liberating large quantities of power.... The seed of a plant contains nitrogenous substances in a far higher ratio than the rest of the plant; and the seed differs from the rest of the plant in its ability to initiate ... extensive vital changes—the changes constituting germination. Similarly in the bodies of animals ... in every living vegetal cell there is a certain part that contains nitrogen. This part initiates these changes which constitute the development of the cell.... It is a curious and significant fact that, in technology, we not only utilize the same principle of initiating extensive changes among comparatively stable compounds by the help of compounds much less stable, but we employ for the purpose compounds of the same general class. Our modern method of firing a gun is to place in close proximity with the gunpowder which we choose to decompose or explode, a small portion of fulminating powder, which is decomposed or exploded with extreme facility, and which on decomposing, communicates the consequent molecular disturbances to the less easily decomposed gunpowder. When we ask