七操の湯
Nanamisao no Yu SpringOperated by · 横湯細惣代 児玉秀樹
硫
Sulfate
+ Chloride
- Color
- nearly colorless and clear
- Taste
- with a slightly salty edge
- Odor
- odorless
Sodium-Calcium Sulfate-Chloride spring
pH 7.3NeutralHot source · 51°C
Composition fingerprint1.4 g/kg dissolved · Hypotonic
Na⁺58
Ca²⁺37
SO₄²⁻50
Cl⁻47
◀ CationsAnions ▶
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Sulfate SO₄²⁻
- "gypsum / Glauber's salt" — vessels and wound healing.
Known good for
- Aches & jointsstiff shoulders
- Circulationtired legs
- Warmingcold sensitivity
A sodium-calcium spring led by sulfate with a chloride sub-type — sulfate gives quiet body, chloride adds a salty edge to the heat-retaining feel. Hot at the wellhead (50.5 °C), neutral in pH, and visually almost colourless with only a faint salty note. Moderately mineralized at 1,418 mg/kg dissolved solids, and notably rich in metasilicic acid (153.8 mg/kg) — that silica leaves a thin moisturising film that makes the water sit smoothly on the skin. A naturally welling source at Yokoyu in Yamanouchi.
Sampled at bath inlet·Analyzed May 26, 2016·一般社団法人 上田薬剤師会 検査センター·Cert no. 中28-4 (No.42)