Definition
Water arising from a salt well that belongs to a person who is not the owner of the soil beneath the well. Boilary is a narrow term of property law describing a specific ownership situation: the right to, or the product of, a salt spring or salt well where the surface rights and the subsurface mineral rights are severed — specifically where the well-owner and the landowner are different persons. The term captures both the water itself and, by extension, the entitlement to that water as against the soil-owner's claims.
Common Language
Modern common usage (Wiktionary): Archaic form of "boilery."
Historical common usage (Webster's 1913): See Boilery — referring to a place or establishment where salt is produced by boiling brine.
The common English sense points toward a place of salt manufacture. The legal meaning is more precise and more proprietary: boilary describes not the facility or process, but the specific legal right to water drawn from a salt well when ownership of the well or its yield is separated from ownership of the land. A researcher encountering the term in a common-language source will miss this property-law dimension entirely.
Why It Matters in Research
Boilary is a relic term that surfaces almost exclusively in older English and early American property materials dealing with salt springs and mineral rights — a context with substantial economic importance before the industrial era, particularly in England and in early American settlements where salt was a critical commodity. Researchers should be alert to several issues:
First, the term encodes a severed-ownership concept. It presupposes split estates — a configuration that generated significant litigation over mineral and subsurface rights. A document using "boilary" is implicitly raising questions about who holds the surface, who holds the mineral interest, and what the well-owner may lawfully take.
Second, the term essentially vanishes from American legal usage after the nineteenth century. Modern mineral rights law, oil and gas law, and water law have absorbed and replaced the conceptual territory boilary once occupied. A researcher tracing the history of split-estate doctrine or subsurface rights will find boilary a useful early marker, but should not expect it in twentieth-century sources.
Third, boilary appears in close proximity in the historical dictionaries to other obsolete terms (bois, bolhagium), which suggests it was already being catalogued as a curiosity rather than active doctrine even when Black's first compiled these entries. Its presence in a legal document is a strong signal that the source is English in origin or heavily influenced by English common law property concepts.
Historical Dictionary Support
Both editions of Black's Law Dictionary define boilary identically: water arising from a salt well belonging to a person who is not the owner of the soil. The definition is terse and unchanged across editions, suggesting neither evolution in legal meaning nor significant litigation history that would have prompted refinement. Neither edition elaborates on the doctrine's application, the remedies available to a boilary-holder, or the mechanism by which such a severance of ownership arose — gaps that a researcher must fill through older English property treatises and records of salt-producing regions.
The placement of the entry in both editions — sandwiched between bois (wood/timber) and bolhagium (a small cottage) — reflects an alphabetical cataloguing of archaic English and Law French property terms rather than any thematic grouping. This context reinforces that boilary belongs to the same stratum of obsolete common law property vocabulary as other terms describing specific resource rights (turbary, piscary, estovers) that defined medieval and early modern land use.
No meaningful divergence exists between the two Black's editions on this term.
Jurisdictional Note
Boilary is rooted in English common law and has no meaningful independent life in American statutory or case law. Its relevance in U.S. research is primarily historical, appearing in early property records and treatises from regions with salt spring activity. Modern split-estate and mineral rights doctrine has entirely supplanted it.