אַשְׁלְגָן (ashlegan) — potassium
Etymology
The word אַשְׁלְגָן is part of a remarkable systematic effort to create Hebrew names for chemical elements. Of the 118 known elements, only 17 are regularly called by Hebrew names in Israeli usage (aluminum and silicon have Hebrew names — חַמְרָן and צֹרָן — but these are rarely used). The Hebrew names that are used fall into several historical groups.
Seven elements are mentioned in the Bible and have ancient names: כֶּסֶף (silver), זָהָב (gold), בַּרְזֶל (iron), נְחֹשֶׁת (copper), בְּדִיל (tin), עוֹפֶרֶת (lead), and גָּפְרִית (sulfur). Most of these are common to all Semitic languages.
Six more elements received Hebrew names in 1886, coined by Lithuanian physician Benjamin Shershevsky and Russian writer Yechiel Michal Pines in their chemistry primer "Mishnat Olam Katan: Breita DeMerkava," published in Jerusalem. Their brilliant innovation was to use the Hebrew noun pattern qatlan (קַטְלָן) as an equivalent to the European suffix "-gen" (from Greek, meaning "producer of"), creating a consistent and productive morphological pattern for element names: חַמְצָן (oxygen, "acid producer"), מֵימָן (hydrogen, "water producer"), פַּחְמָן (carbon, from פחם, coal), שִׂידָן (calcium, from שיד, lime/chalk), זַרְחָן (phosphorus, "light bearer"), and חַנְקָן (nitrogen, "choker/suffocator").
The element כַּסְפִּית (mercury) received its Hebrew name from Pines alone in his 1897 book "Ha-Koah," shortening the traditional phrase "כסף חי" (living silver, used since the 11th century — Rashi translated the French vif-argent). The element אָבָץ (zinc) was coined by Eliezer Ben-Yehuda, first appearing in his dictionary's first fascicle in December 1900, derived from the Aramaic word avtza/avtza (used in Targum Onkelos to translate "tin" in Numbers 31:22).
The remaining two, נַתְרָן (sodium) and אַשְׁלְגָן (potassium), were coined by the Language Committee (Va'ad HaLashon) and appeared in their chemistry terminology list published in 1928. Potassium was discovered and named "Sodium" by Humphry Davy in 1807, but was also called "Natronium" by Ludwig Wilhelm Gilbert in 1809, from the Latin nitrum (sodium carbonate), which itself came from the Greek nitron, which came from Semitic languages (possibly Phoenician). The corresponding Hebrew word נֶתֶר appears in the Bible, so the Language Committee named the element נַתְרָן.
For potassium, Davy named it "Potassium" in 1807, derived from "potash." The Hebrew word אַשְׁלָג (ashlag), meaning potash, appears in Talmudic literature — including the Mishnah (Shabbat 9:5), where it appears among laundering materials. The word אשלג is apparently derived from the Akkadian ashlaku, meaning "cleanser." The precise identification of the substance has been debated — it might be the plant Salsola kali. In 1900, Yehuda Gur and Yosef Klausner assigned the meaning "potash" to אשלג in their pocket dictionary. From this, the Language Committee derived אַשְׁלְגָן as the name for the element potassium.
Key Quotes
"מי רגלים, נתר, ובורית קימונייה ואשלג כדי לכבס בהם בגד קטן כשבכה" — משנה, שבת ט׳, ה׳
"המלות המלאכותיות שנבראו בספרך זה ברוח השפה העברית נבראו" — יחיאל מיכל פינס, הקדמה ל״משנת עולם קטן״, 1886
Timeline
- ~200 BCE–200 CE: אַשְׁלָג appears in Mishnah as a laundering substance
- 11th century: Rashi uses phrase "כסף חי" (living silver) for mercury (translating French vif-argent)
- 1807: Humphry Davy discovers and names potassium ("Potassium") and sodium ("Sodium")
- 1809: Ludwig Gilbert proposes "Natronium" for sodium
- 1886: Shershevsky and Pines coin חמצן, מימן, פחמן, שידן, זרחן, חנקן in Jerusalem
- 1897: Pines coins כספית for mercury
- December 1900: Ben-Yehuda coins אבץ for zinc; Gur and Klausner assign "potash" meaning to אשלג
- 1928: Language Committee publishes chemistry terminology; coins נַתְרָן and אַשְׁלְגָן
Related Words
- נַתְרָן — sodium (from biblical נֶתֶר, also coined in the 1928 list)
- חַמְצָן — oxygen (coined by Shershevsky & Pines, 1886)
- מֵימָן — hydrogen (coined by Shershevsky & Pines, 1886)
- פַּחְמָן — carbon (coined by Shershevsky & Pines, 1886)
- אָבָץ — zinc (coined by Ben-Yehuda, 1900)
- כַּסְפִּית — mercury (coined by Pines, 1897)
- אַשְׁלָג — potash (Talmudic word, source of אשלגן)