It was recommended that people used burnt hartshorn, the burnt shells of snails and burntgypsum.
有人建议人们使用烧过的鹿角、烧过的蜗牛壳和烧过的石膏。
2
The difference of effects of burnt lime and hydrated lime, raw gypsum and burntgypsum on white cement was studied, and the optimal type of lime and gypsum was determined.