地域観光資源の 多言語解説文データベース

Saltpeter Production

Traditionally, one of the main industries in Shirakawa-go was the production of saltpeter (potassium nitrate) from the mineral niter, an essential ingredient in gunpowder. The required techniques were introduced from nearby Gokayama, where the industry had grown exponentially after the introduction of European matchlock guns in 1543.

Villagers made saltpeter in a hole up to 2 meters deep under the irori fireplaces of the gassho-style houses. The hole was filled with a mixture of materials including straw, soil, mugwort, and silkworm excrement, then left to ferment for three to four years. Over time, calcium nitrate formed in the soil through the nitrification of bacteria. This soil was sold to one of the three licensed refineries in Shirakawa-go, where it was mixed with water, concentrated through heating, and refined into liquid potassium nitrate. The liquid was then filtered, boiled down and condensed, and then cooled to obtain saltpeter crystals.

The refineries sold the saltpeter to domains and traders as far away as Osaka. The saltpeter industry flourished until the Meiji era (1868–1912), when a cheap alternative was imported from Chile, resulting in a decline in local production.

火硝生產

製造火硝（硝酸鉀），向來就是白川鄉的一大傳統主要產業。火硝生產技術來自鄰近的五箇山，該地區的這項產業自1543年引入歐洲火槍之後急劇發展起來。

白川鄉的村民在「合掌造」民居一樓的「圍爐裏」（用以烹飪和取暖的地爐）旁挖掘一個約2公尺的深坑，用於製造火硝。坑內填滿了包括稻草、泥土、艾草、蠶糞等原料，放置三到四年等待它們發酵。在這期間，由於細菌的硝化作用，泥土中會生成硝酸鈣。村民們把經過發酵的泥土出售給被稱為「上煮屋」的精煉廠，白川鄉共有3家這樣擁有正規生產許可的工廠。工廠將泥土與水混合，加熱濃縮，提煉出液態的硝酸鉀。隨後再對這些液體進行過濾、蒸餾濃縮、冷卻，最終加工出硝酸鉀結晶。

精煉廠將硝酸鉀晶體賣給周邊各藩和相關商人，銷售範圍遠至大阪。白川鄉的火硝生產一度十分繁榮，但在進入明治時代（1868-1912）後，因來自智利的廉價替代品，當地產業逐步走向沒落。

火硝生产

火硝（硝酸钾）制造向来就是白川乡的一大传统支柱产业。火硝生产技术来自邻近的五箇山，那里的火硝制造业在1543年引进欧洲火枪后便开始急剧增长。

白川乡的村民会在“合掌造”民居一楼的“围炉里”（用以烹饪和取暖的地炉）旁挖掘一个2米左右的深坑，用于制造火硝。坑内填满稻草、泥土、艾草、蚕粪等原料，放置三到四年，等待它们发酵。在这期间，由于细菌的硝化作用，泥土中会生成硝酸钙。村民们把发酵后的泥土卖给被称为“上煮屋”的精炼厂，白川乡共有3家这样拥有正规生产许可的工厂。工厂将泥土与水混合，加热浓缩，提炼出液态的硝酸钾。之后，再通过过滤、蒸馏浓缩、冷却等工序，最终将液态硝酸钾加工为硝酸钾结晶。

精炼厂将硝酸钾晶体卖给周边各藩和相关商人，销售范围远至大阪。白川乡的火硝生产一度十分繁荣，但在进入明治时代(1868-1912)后，受到来自智利的廉价替代品冲击，本地产业逐步走向衰落。