Nitro-aerial

With regard to fire, it is to be noted that for the burning of things, it is necessary that nitro-aerial particles should either be already in the burning mass or be supplied from the air. Gunpowder burns very readily on account of the nitro-aerial particles it contains plants burn partly from the nitro-aerial particles they contain, and partly from such as come from the air but sulphureous matter, pure and simple, can only be ignited by nitro-aerial particles supplied by the air. ... 

Mayow advances many speculations as to the functions of the nitro-aerial spirit, which show that he does not distinguish clearly between this spirit and the phenomena of heat generally, as in producing rigidity in bodies, and in affecting their elasticity, and that the elastic power of air is due to nitro-aerial spirit. He arrives at these conclusions on the basis of experiments described, but often misinterpreted. 

The similarity of respiration to ordinary combustion Mayow clearly comprehended. He cites the previous observation of Lower that the venous blood becomes bright red by the air in the lungs. Mayow cites experiments to show that blood which has been kept some time in a glass vessel and is bright red only at the surface, when placed under the air pump, will at the surface effervesce gently and rise in bubbles, but fresh arterial blood on the other hand will, in vacuo, expand remarkably and rise in an almost infinite number of bubbles. Mayow considers that the nitro aerial spirit thus absorbed in the lungs by the blood plays the same part as in other combustions and this accounts for the heat of the animal body. 

In 1776, A. L. Lavoisier demonstrated the presence of oxygen in nitric acid, and this discovery recalls J. Mayow s nitro-aerial particles in 1784, H. Cavendish synthesized it by the action of electric sparks in humid air, and proved that it contained oxygen and nitrogen and in 1816, J. L. Gay Lussac, and C. L. Berthollet established its exact composition. 

But I am still not ready to discount Mayow and Boyle. Mayow says the flame goes out because nitro-aerial particles are used up from the air—what Boyle would call ether—and though plenty of air remains in the flask, it is these particles that are needed for combustion. ... 

By the end of the talk, the room was so smoky that several ladies had to be escorted out. Wepfer said that there was time for only three questions. My hand shot up, and he turned to me with amusement. I wonder if you are familiar with John Mayow and his conclusions about fire and air I asked. His smile faded, but he nodded gravely. Then you ll know that Mayow noticed that if a mouse was placed under a glass, it could not live after part of the air—the part he called the nitro-aerial spirit—had been consumed, even though some air was left in the glass. Likewise with a candle flame. How does Mayow s theory that air in fact consists of at least two different parts fit your theory of the Archaeus, which you say is a force separate from the air ... 

In fact, the next phase was the most lethal of all and had always marked the end of our alchemical adventure. Whereas the distillation is a delicate stage of the process, the next requires the addition of volatile saltpeter to the mixture, and this causes an explosion that results at worst in the sudden death of the alchemist and at best an end to all his hopes. Mayow says the combination of fixed salt with nitro-aerial particles causes niter to fly off like smoke. And Sir Thomas Browne says the explosion of gunpowder is due to the generation of a large bulk of air by the antipathetic reaction of saltpeter to sulfur. 

But there must be a relationship. And something else. The fire sought the higher part of the room. I fell back on the floor and saw it race above my head, and that s why I wasn t badly burned. Mayow says that animals die and flames go out faster in the upper part of a vessel because the air that is expired is lighter once deprived of the dense, nitro-aerial particles needed for life. I believe he was right about air consisting of different types of particles. ... 

Not until the seventeenth century was doubt cast on the notion that air was one of the basic elements. A Dutch physician and naturalist, Herman Boerhaave (1668-1738), was the first to suspect that there is some lifesupporting ingredient in the air that is the key to breathing and combustion. The chemists will find out what it actually is, how it functions, and what it does it is still in the dark, Boerhaave wrote in 1732. Happy he who will discover it. 3 In England, the brilliant scientist Robert Boyle (1627-1691) also maintained that some life-giving substance, probably related to those needed for maintaining a flame, was part of the air. The English physician and naturalist John Mayow (1645-1679) claimed that nitro-aerial corpuscles 4 were responsible for combustion. 

Nitro-aerial because they occur also during combustion of saltpeter. 

GUN POWDER, LIGHTNING AND THUNDER, AND NITRO-AERIAL SPIRIT 217... 

FIGURE 150. This plate is from John Mayow s Tractus Quinque Medico Physici Ox-ford, 1674). It shows his experiments in which nitrO aerial spirit in saltpetre was trans ferred to antimony under a heating glass. In effect oxygen was transferred between the two substances (from the Dr. Roy G. Neville Historical Chemical Library, a collection in the Othmer Library, CHF). 

The Tractatus Quinque concerned itself with other scientific questions beyond the medical, physiological, and chemical. For example, Mayow discussed the origins of water spouts as due to air turbulence (see Figures 151 and 152 see also Benjamin Franklin s studies of these phenomena and Figure 119 later in this book). Mayow s explanation of lightning and thunder are reminiscent of those of Paracelsus and imagine explosions between nitro-aerial spirit and sulphureous matter in the atmosphere. 

W. Hewson, E eriments on the Blood, Phil. Trans., 1770, lx, 368-413 (373) repr. in lus Experimental Inquiries Part the First. Being a Second Edition of an Inquiry into the Properties of the Blood, 1772, 10 The Works of William Hewson, ed. G. Gulliver, 1846, 11 (the note says perhaps Mayow s nitro-aerial spirit may be here confounded with nitre ). 

A strenuous advocate of the view that spirit of nitre was the active principle in the blood, in Tractatus Quinque, Mayow claimed that animal spirits consisted mainly of nitro-aerial particles, i.e., very rareified, elastic and agile particles, which, combined with salino-sulphurous particles contained in blood, gave origin to muscular motion. 

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