四の湯温泉
Shinoyu Onsen湯
Simple
- Color
- colorless and clear
- Taste
- tasteless
- Odor
- odorless
Sodium Chloride-Sulfate-Bicarbonate spring
pH 7.7Weakly alkalineHot source · 45°CHigh silica
Composition fingerprint0.7 g/kg dissolved · Hypotonic
Na⁺75
Cl⁻44
SO₄²⁻27
HCO₃⁻26
◀ CationsAnions ▶
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Chloride Cl⁻
- table-salt anion — coats the skin and holds heat in.
Known good for
- Aches & jointsstiff shoulders
- Smooth skindry, rough skin
- Recoveryfatigue, stress
A gentle simple thermal spring: weakly alkaline, soft on the skin, and only lightly mineralized, so it sits easy on the body rather than announcing itself. Sodium leads the cations, while chloride, sulfate and bicarbonate share the anion side almost evenly and none of them in quantity. What stands out instead is metasilicic acid at 180 mg/kg — the silica that leaves a thin moisturizing film and puts this water squarely in Japan's beauty-water family. The sample was drawn at the storage tank rather than at the wellhead, and a companion certificate for the same source takes its sample at an on-site drinking fountain.
Sampled at mixing tank·Analyzed Jul 24, 2018·公益社団法人大分県薬剤師会·Cert no. 大薬検 第7R-30070012号