History of chemistry

"[T]here is a similarity easily detected between the hieroglyphics and the alchemical signs. The phraseology in the early treatises is similar to that in the priestly writings."

"[N]ote the important part played by the number four with the alchemists as well as with the Egyptian priests. There are the four bases or elements, the tetrasomy of ; the four zones, four funeral deities, four cardinal points, four winds, four colors, etc."

"The ns, as masters of occult sciences, played an important part at Rome. In much earlier times, the Bible mentions them as the depositaries of all wisdom and science... They were rivals of the Egyptians in knowledge, and were especially famous as astrologers. Many industrial arts were brought to as high perfection in as in Egypt; for instance, the processes of glass-making, of dyeing, and of working in metals. Those Chaldeans who settled in Rome in later years came from Syria and . Tacitus makes mention of them. They were much sought after by the fashionable as the representatives of Eastern religions and mystic doctrines."

"Ostanes, the Mede, was one of the celebrated early alchemists. Several writers have recorded for us the existence of a book called The Book of the Divine Prescriptions, which seems to have been the most famous writing of these Persian sages."

"The belief in some wonderful connection between planets and metals is due to these ns. The signs of the heavenly bodies became the symbols for the metals. These planets influenced a supposed growth of the metals, and were esteemed all-powerful in regulating human life and fate. Many of these notions are to be attributed to the Alexandrian epoch."

"Observations of the changes which are constantly happening in the sky, and on the earth, must have prompted men long ago to ask whether there are any limits to the changes of things around them. And this question must have become more urgent as working in metals, making colours and dyes, preparing new kinds of food and drink, producing substances with smells and tastes unlike those of familiar objects, and other pursuits like these, made men acquainted with transformations which seemed to penetrate to the very foundations of things."

"Some of the Greek philosophers who lived four or five hundred years before Christ formed a theory of the transformations of matter, which is essentially the theory held by naturalists to-day. ...Those investigators attempted to connect all the differences which are observed between the qualities of things with differences of size, shape, position, and movement of atoms... unchangeable, indestructible, and impenetrable particles ...not one of them can be destroyed, nor can one be created; when a substance ceases to exist and another is formed, the process is not a destruction of matter, it is a re-arrangement of atoms."

"The first principle in nature is asserted by Lucretius [Concerning the Nature of Things] to be that " Nothing is ever gotten out of nothing.""

"We now know that many compounds exist which are formed by the union of the same quantities by weight of the same elements, and, nevertheless, differ in properties; modern chemistry explains this fact by saying that the properties of a substance depend, not only on the kind of atoms which compose the minute particles of a compound, and the number of atoms of each kind, but also on the mode of arrangement of the atoms. The same doctrine was taught by Lucretius, two thousand years ago. " It often makes a great difference," he said, " with what things, and in what positions the same first beginnings are held in union, and what motions they mutually impart and receive.""

"Lucretius pictured a solid substance as a vast number of atoms squeezed closely together, a liquid as composed of not so many atoms less tightly packed, and a gas as a comparatively small number of atoms with considerable freedom of motion. Essentially the same picture is presented by the molecular theory of to-day."

"Another objector urges—"You say the atoms are always moving, yet the things we look at, which you assert to be vast numbers of moving atoms, are often motionless." ...Lucretius answers by an analogy. " And herein you need not wonder at this, that... since they are themselves beyond what you can see, they must withdraw from sight their motion as well; and the more so, that the things which we can see do yet often conceal their motions when a great distance off.""

"More than two thousand years passed before investigators began to make accurate measurements of the quantities of the substances which take part in those changes wherein certain things seem to be destroyed and other totally different things to be produced; until accurate knowledge had been obtained of the quantities of the definite substances which interact in the transformations of matter, the atomic theory could not do more than draw the outlines of a picture of material changes. A scientific theory has been described as "the likening of our imaginings to what we actually observe." So long as we observe only in the rough, only in a broad and general way, our imaginings must also be rough, broad, and general."

"The atomic theory was used by the great physicists of the later Renaissance, by Galileo, Gassendi, Newton and others. ... John Dalton, while trying ...to form a mental presentation of the atmosphere in terms of the theory of atoms, rediscovered the possibility of differences between the sizes of atoms, applied this idea to the facts concerning the quantitative compositions of compounds which had been established by others, developed a method for determining the relative weights of atoms of different kinds, and started chemistry on the course which it has followed so successfully."

"[M]any chemical facts, products, and processes have been known from a period considerably earlier than any of which we have a historic record. As a true science... chemistry is only between one and two hundred years old... but... it has been known and practised as an art continuously since prehistoric times. The skilled, and often royal or priestly, artisans handed down its secrets in the shape of workshop traditions, from the earliest ages till the present day..."

"The origin of the science of chemistry must... be sought in the art of alchemy. ...[I]n the course of their labours they gained much definite information regarding the properties of metals and other substances, devised the necessary apparatus and processes for chemical operations, and laid a foundation upon which later investigators have built up the modern science."

"[T]he Alchemical Period... may with propriety be called "The Ancient History of Chemistry.""

"The application of the term [alchemy] has frequently but wrongfully been restricted to the pretended arts of making gold and silver, and the more profitable arts of adulterating and of imitating gold. It had, however, a wider application, and ought to be regarded as including all the arts known in ancient times which dealt with things now comprehended in the science of chemistry."

"The use of the expression "chemist" to indicate a druggist reminds us of another branch of alchemy, the art of making drugs which received much attention in Ancient Egypt, and probably in other eastern countries, and was combined with the art of preparing poisons and their antidotes."

"The ancient Egyptians... had a profound knowledge of the art of making, tinting, and working glass."

"The arts and industries of dyeing, painting, and staining were known and practised in eastern lands in very ancient times. ...[T]he dyeing of skins and garments... is mentioned in most writings of antiquity. The colours used in early Egyptian art remain bright and clear. ...Remains found in Chaldea include coloured articles, as well as articles made of metal."

"We are apt to suppose that the use of s is of modern origin, but that is not so. Not only did the Hebrews and the Greeks employ antiseptics in their religious rites, but in Egypt a very high degree of skill must have been attained in their preparation and use, before the body of King Rameses... and hundreds of others could have been preserved for between three and four thousand years so perfectly..."

"The development of the paraffin and other hydrocarbon industries during the present generation may make us fancy that this is a modern discovery; but it is the fact that the fire on the Hebrew altar fed by the Jewish priests was our familiar petroleum and was called r or nephi, a Hebrew word signifying purification..."

"[T]he first period [prehistory to 500 B.C.] into which the history of chemistry naturally divides itself is that during which a number of chemical facts were known, but not understood or explained. These facts were not correlated, nor was the subject studied with scientific purpose and method, consequently during this period chemistry was not a science."

"The Greeks were no chemists. The bent of their mind was not towards natural science; few observations or experiments were made by them, and they preferred to argue from general principles to particulars, rather than from particular observations to general principles."

"Davy held that if the battery is strong enough any compound may be decomposed, and that chemical affinity is merely a form of electric attraction. He vigorously put his theory into practice..."

"Berthollet's conclusion that chlorine is oxymuriatic acid was universally accepted until Gay-Lussac and Thénard in 1809 endeavoured to decompose the gas and failed. They concluded that it contained water because it yielded water when passed over litharge. Their researches read to the Institute in 1809 led Davy to investigate muriatic acid (hydrochloric acid) gas, which in 1808 he had shown to be decomposed by potassium, with evolution of hydrogen. In 1810 he proved that chlorine is an element, and that muriatic acid gas is a compound of chlorine and hydrogen. He thus overturned the oxygen-acid theory, and demonstrated that muriates are compounds of metals with chlorine. He pointed to the fact that some acids, such as sulphuretted hydrogen, contain no oxygen, and argued that muriatic acid gas was one of these, chlorine in it taking the place of oxygen. ...The conclusions of Davy were at first doubted, but when iodine and bromine were also discovered, Gay-Lussac and his followers adopted Davy's views. The latter worked out fluorine, and proved that hydrofluoric acid (HF) contains no oxygen. Berzelius also opposed Davy until the discovery of iodine, but embraced the latter's opinion in 1820."