Definition
The gramme is the base unit of mass in the metric system, defined as the weight of one cubic centimeter of distilled water at a temperature of 4° Celsius. It equals 15.4341 grains troy or 5.6481 drachms avoirdupois. "Gramme" is the older French-derived spelling of what modern usage renders as "gram." The term appears in legal texts, statutes, treaties, weights-and-measures regulations, and pharmaceutical standards from the nineteenth and early twentieth centuries wherever metric measurement was adopted or referenced.
Common Language
Modern common usage (Wiktionary): Alternative spelling of gram.
Historical common usage (Webster's 1913): Same as gram the weight.
The common and legal meanings are essentially identical here. The only gap worth noting for researchers is orthographic: legal and scientific documents before the mid-twentieth century consistently use the French spelling "gramme," while modern statutes and regulations use "gram." A researcher scanning historical legal sources for metric-weight provisions must search both spellings.
Why It Matters in Research
The primary research challenge with this term is spelling variation across time and jurisdiction. Nineteenth-century Anglo-American legal texts — statutes, treaties, pharmacopeias, and customs regulations — almost uniformly adopt the French spelling "gramme," reflecting the term's direct importation from the French metric system established after the Revolution. By the mid-twentieth century, U.S. federal legislation and international standards bodies shifted to "gram," while British and Commonwealth sources retained "gramme" longer. A corpus search limited to one spelling will miss a substantial portion of relevant documents.
The term surfaces most frequently in three legal contexts: (1) customs and tariff law, where imported goods measured by metric weight required precise conversion for duty assessment; (2) pharmaceutical regulation, where drug quantities in prescriptions, pharmacopeias, and later food-and-drug statutes were expressed in grammes; and (3) weights-and-measures legislation, where legislatures adopting or permitting the metric system defined the gramme as the foundational unit.
Researchers working in pre-1900 sources should also be alert to the conversion figures that accompany the definition — 15.4341 grains troy and 5.6481 drachms avoirdupois — because these conversion ratios appear in customs disputes and pharmaceutical cases where the accuracy of a metric-to-avoirdupois conversion was contested.
Historical Dictionary Support
The three source dictionaries agree on the physical definition: the gramme is the weight of one cubic centimeter of distilled water at 4° Celsius, equal to 15.4341 grains troy. Black's (2nd ed.) and Bouvier's are substantively identical on this point and can be treated as reliable cross-confirming sources for the scientific baseline.
Black's (1st ed.) presents a curious anomaly. Its entry conflates two distinct definitions: it opens with the correct statement that the gramme is the unit of weight in the metric system, but then appends the sentence "The gramme is the weight originally transferred from the builder to the owner, or first purchaser" with a citation to 3 Kent's Commentaries 133. This second sentence has nothing to do with the metric unit — it almost certainly reflects a typesetting or editorial error in which text from an adjacent or nearby entry (likely relating to the transfer of title or the passage of risk) was accidentally incorporated. Researchers should treat this passage in Black's (1st ed.) as corrupted and rely on Black's (2nd ed.) or Bouvier's for the definition.
None of the historical dictionaries address the shift from "gramme" to "gram" as standard spelling, nor do they discuss the legal consequences of that orthographic evolution. This is a gap researchers must fill through legislative and regulatory history rather than dictionary sources.
Jurisdictional Note
The United States did not mandate the metric system but legalized its use by statute beginning in 1866. British and Commonwealth jurisdictions used "gramme" as the standard spelling in official documents well into the twentieth century. Continental European legal systems, working directly from French metric law, used "gramme" throughout the nineteenth century. Modern U.S. federal law uses "gram."