In conection with the study of influence of dispersing agents on the setting of portland cement, the solubilities of calcium sulfate dihydrate and hemihydrate in aqueous solutions of calcium lignosulfonate, sodium lignosulfonate and gluconic acid were determined at 25°C. The solubility of hemihydrate coresponds to the supersolubility of dihydrate and the supersaturated solution is generally unstable. Hence the separation of liquid phase was carried out during the electric conductivity of the mixture had constant value. The experimental results are as follows.
(1) Sodium lignosulfonate and gluconic acid increase the solubility of both sulfates with the increase of their concentration.
(2) Calcium lignosulfonate and commercial dispersing agents containing principally calcium lignosulfonate decrease the solubility of both sulfates with the increase of their concentration.
(3) The degree of supersaturation of dihydrate in solutions containing above mentioned substances was discussed.

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The dolomite bearing limestone of Permian is distributed extensively near Mt. Funafuse, Gifu Prefecture, central Japan. The dolomite deposit of this area was first surveyed and reported by T. Anzai in 1956 and later by S. Kawata in 1960, who described chiefly about the distribution and quality of the deposit occuring at the area near Konjima and Iodo, between the Embara river and the Kanzaki river.
The writer has studied the geology of Permian of the northern part of Yamagata-gun, Gifu Prefecture since 1960, and has observed some other dolomite deposits occuring west of the Kanzaki river as well as east of the Embara river.
It can be mentioned that the dolomite deposits in the limestone are divided into two types according to their facies. One is white or whitish gray in color and has a vast area of distribution with many intercalations of schalstein and chert, whereas the other is black and accompanied scarcely by non-calcareous rocks, though both are considered to be of the same horizon paleontolo-gically.
The dolomite is observed to turn vertically and horizontally into the country rock of limestone from which some important fossils of Fusulinids such as Pseudofusulina, Acervoschwagerina, Parafusulina, Neoschwagerina, etc. were collected.
Judging from the fossils, the dolomite is featured with middle the Permian because Parafusulina could be collected in abundance from the limestone intercalated in or adjacent to the dolomite.
The dolomite deposits occur in many places in the Permian rocks in Mino Mountainland and Hida Massif, particularly more in Mino than in Hida.
In Mino Mountainland, they distribute from Mt. Funafuse towards Mt. Ibuki with the direction of northeast to southwest and most of them are featured with Parafusulina zone containing Parafusulina. In Hida Massif, however, the distribution of the deposits takes the direction of west to east from Nyukawa towards Shirahone spa and they are also featured with Parafusulina zone containing Pseudofusulina abundantly instead of Parafusulina.

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昭和38年度から石膏と石灰誌にマグネシアが仲間入りすることとなったが, まことに喜ばしい次第で本会におけるこのものの一層の研究の進展を期待している。筆者らは数年来, ジャモン岩から高純度マグネシアの分離, 取得に関する研究にたずさわってきた関係上, 従来からマグネシアに深い関心を有するわけである。今回非才を顧みず, 乏しい経験をもとにして, 本誌上に研究結果, 私見などを述べさせていただくことにした。

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