| In ancient times, the Egyptians and Greeks defined | | | | two are brought together…and the one part has |
| certain substances based upon their taste. Both the | | | | overcome and killed the other, neither liquor nor a |
| Greeks and the Egyptians had discovered that one | | | | spiritus acidus can be found in their dead bodies, but |
| particular substance was very sour. This became to | | | | the same has been made, as both were before and |
| be known as vinegar, which was produced from the | | | | from which they were derived, namely ordinary |
| fermentation of fruits to produce wine. Therefore, a | | | | saltpeter (potassium nitrate salt).” |
| new categorization of substances was developed that | | | | This observation that an acid and alkali react to yield a |
| included all things that were sour. | | | | salt was a big advancement in acid-alkali alchemy. In |
| The Greeks were also familiar with a different | | | | fact, this led Glauber to find another important chemical |
| category of substances. They found three slippery | | | | salt. From one of his experiments, Glauber found that |
| substances left behind as residue after burning certain | | | | when spirit of alum (sulfuric acid) was reacted with |
| materials. These three substances were: potash, | | | | ordinary table salt, a new salt was produced. This |
| soda, and lime. Potash, which must have been the | | | | salt was sal mirabilis (sodium sulfate), which was also |
| first to be discovered, was produced from wood | | | | called Glauber’s salt. By producing many |
| ashes. When some waters were produced and | | | | unattained compounds (hydrochloric acid, nitric acid, |
| allowed to evaporate, the film left behind was soda. | | | | sulfuric acid, sodium sulfate, etc.), Glauber’s |
| Lime was produced from burning seashells. | | | | contributions to alchemy were very important. |
| Ultimately, the Greeks discovered a new category to | | | | With the discoveries presented by Glauber, the |
| define substances based upon the property of feeling | | | | chemical world added another terminology that was |
| slippery. | | | | now broken into three categories: acid, alkali, and |
| In 1386, to build on the Greek’s definition of sour or | | | | salt. What are the properties of these three |
| slippery, a new terminology was developed to speak | | | | categories that make them different from one |
| about things that felt slippery. From the Arabic word | | | | another? |
| al-qaliy, which means “the ashes”, the term | | | | Robert Boyle was born in Ireland where he grew up |
| alkaline was developed. This word was then used to | | | | until he was eight years old. He was then sent to |
| speak about things that felt slippery. | | | | school and traveled around Europe with a French |
| During the middle ages, the advancement towards | | | | tutor. After his stint of traveling and studying, Boyle |
| defining sour and slippery substances was slow. | | | | returned to Ireland where he joined the Invisible |
| European trading with China led to the introduction of | | | | College. The Invisible College was not actually a |
| the highly valued clothing good, silk. During the 16th | | | | college at all; it was a group of prominent philosophers |
| century in France, fabric dyers found that when | | | | who inquired about questions relevant to the time |
| particular chemicals were added to the dying agent, | | | | period. This group later became the Royal Society of |
| the colors became more vibrant and even changed | | | | London for the Improvement of Natural Knowledge |
| colors. Deeper and richer colors could be produced | | | | after it had been granted by the King of England. |
| by adding these chemicals to the dying vats. The | | | | Boyle was named to the council and held an important |
| dyers noticed that when one chemical was added to | | | | role in the Royal Society. |
| the vat, it turned the dye a red color. On the other | | | | During the 17th century, the majority view of |
| hand, when a different chemical was added to the vat, | | | | compounds suggested that all chemical compounds |
| it turned the dye to a bluish-green color. | | | | are composed of the same four elements: fire, earth, |
| The fabric workers understood that certain | | | | water, and air. For example, when a log is burned in |
| substances changed the color and intensity of the | | | | a fire, it leads to the four elements. The log begins to |
| dyes used in the industry. At that time they did not | | | | combust (fire), sap flows from the wood (water), |
| need to know how it worked; they just needed to | | | | smoke rises from the log (air), and the ashes (earth) |
| know that the dyes changed colors. For this reason, | | | | are left behind after the log is finished burning. Boyle |
| the fabric workers did not know that the dyes | | | | disagreed with this hypothesis and suggested that |
| introduced another method for distinguishing between | | | | differences in compounds were to “different |
| substances the Greeks defined as sour and slippery. | | | | textures” (configuration and cohesion of different |
| Also, there was not a good understanding of the | | | | elements). For this reason and many others, Boyle |
| definition of alkaline, except that alkali substances were | | | | was known as the “skeptical chemist”. In fact, |
| slippery. Therefore, the phenomenon was overlooked | | | | Boyle wrote his first book The Skeptical Chemist, |
| by the fabric workers and science all together. | | | | which questioned the majority views of alchemy. |
| As trading with China’s silk continued, Europeans | | | | Boyle found Glauber’s work interesting. The new |
| were also obtaining precious metals such as gold and | | | | category of salts intrigued him and helped to support |
| silver. However, these metals were often mixed | | | | his hypothesis that not everything is composed of the |
| together to produce an alloy. In 1626, an attempt to | | | | same four elements. Boyle began experimenting with |
| separate gold from silver led to an important | | | | acids and alkalis. From his experiments, he was able |
| advancement towards understanding substances that | | | | to fit a better definition of an acid and alkali. On top |
| were only definable by their taste and texture. It was | | | | of what the Greeks and Egyptians defined as being |
| found that the sour substances defined by the Greeks | | | | sour and what metal purifiers noted as excellent |
| also could dissolve silver. When a sour substance | | | | solvents, Boyle added that acids could also precipitate |
| was added to the gold/silver alloy and allowed to boil, | | | | certain substances. Acids were very good in |
| the silver dissolved. After the solid gold pieces were | | | | precipitating sulfur. On top of what the Greeks |
| removed, the silver was then re-obtained by allowing | | | | defined as being slippery, Boyle noticed that alkalis also |
| the sour substance to boil away. This discovery of | | | | contained “detergent properties”. Alkalis were |
| the dissolving properties of sour tasting substances led | | | | also good at dissolving sulfur and oils; and just like |
| to a new terminology. From the Latin word acidus, | | | | Glauber, he found that alkalis were good at |
| which means “sour”, the term acid was | | | | counteracting the properties of acids. He also noticed |
| developed. This term was then used to define sour | | | | that some chemicals do not fit into the category of an |
| tasting substances that had dissolving properties. | | | | acid or alkali. |
| Johann Rudolph Glauber began as a pharmacist; | | | | Boyle continued his research of acids and alkalis and |
| however, he soon changed his line of work and | | | | began to conduct experiments concerning how to |
| became an alchemist. Living in Amsterdam, Glauber | | | | identify an acid or alkali using indicators. He set up a |
| ran many experiments concerning acids and alkalis, | | | | number of different experiments which he published in |
| which were not yet distinctly defined. In his laboratory, | | | | his 1664 book Experimental History of Colours. Boyle |
| he ran many experiments and observed their | | | | knew from the French silk dyers that dyes were |
| reactions. A few significant discoveries Glauber | | | | made from plant juices, so he began to experiment |
| made were that of spiritus salis (hydrochloric acid), | | | | with the affects of acids on certain plant juices. He |
| spirit of alum (sulfuric acid), and spiritus acidus nitri (nitric | | | | discovered what the French dyers had known a |
| acid). Spirit of alum and spiritus acidus nitri were used | | | | century before, only now he understood why the |
| for separating gold and silver; however, he was the | | | | phenomenon they observed occurred. He noted that |
| first to produce concentrated amounts of either | | | | when an acid is placed in a jar containing a purple plant |
| chemical. From his experiments of these three | | | | juice, the solution becomes red. Also, when an alkali is |
| compounds with various chemicals, Glauber noticed | | | | reacted with the same purple plant juice, the solution |
| that some chemicals reacted violently with one | | | | becomes bluish-green. Boyle had rediscovered an |
| another producing an effervescence effect. | | | | interesting and useful means of testing if a chemical |
| In 1658, he described these violent reactions as being | | | | was acidic or alkaline. |
| a “battle”: | | | | The development of acid and alkali indicators did not |
| “When nitri fixi (potassium carbonate, a base) is | | | | stop there. Boyle began to create small pieces of |
| added to spiritom nitri (nitric acid)…the spiritus acidus | | | | paper that had been soaked in lichens juice. After |
| and liquior fixus have slain each other” | | | | the paper had been removed from the juice and dried, |
| The fact that acids and alkalis “battle” one | | | | it became a soft purple color. When the paper is |
| another is not the only significant discovery made by | | | | touched to something acidic in character, the paper |
| Glauber. Also in 1658, Glauber noted that when an | | | | becomes red. Likewise, when the paper is touched |
| acid and an alkali react, they produce a new kind of | | | | to something alkaline in character, it becomes |
| compound called a salt: | | | | bluish-green. This new technique uses the same |
| “Liquor fixus (potassium hydroxide alkali) and spiritus | | | | concept as the plant juice testing, but it is made much |
| acidus nitri (nitric acid) are in their nature…totally unlike, | | | | simpler by touching paper to the sample. |
| foes and adversaries of each other…and when the | | | | |