(I) 100g of sweet-potato powder (40 mesh) was extracted seven times with 550cc of petroleum ether (b. p. 60°-70°C), divided into seven portions: 200, 100, 50, 50, 50 50 and 50cc. The combined extract was concentrated to 50cc under reduced pressure. The concentrated matter was saponified with 20cc of 5% alcholic KOH overnight at room temperature, and after washing with water the concentrated carotene was obtained by evaporating under reduced pressure. The concentrated carotene from carrot powder was compared with that of the sweet potato under the same conditions. (II) The raw material of sweet-potato “Yo No. 7”, after crashing and pressing, was separated into juice and pressed residue. By this treatment, carotene in raw material was divided into juice and pressed residue, 64% and 36% respectively. By heating the juice above 80°C, coagulated matter was obtained. This coagulated matter was the concentrated substance that contained much more carotene than raw material, but the amount produced was poor.
Similarly the part 1, comparative studies are made on the girth of the chest ratio, the sitting height ratio, Rohrer's index, Kaup's index and the girth of the upper arm of blind and normal school-children (6-19 year) in four prefectures of Tohoku district, and the following characteristics are found. (1) In the weight and the girth of the chest, blinds are not so inferior to normals as in the height, therefore the girth of the chest ratio and Rohrer's index of blinds are somewhat greater than normals'. (2) The sitting height ratio of blinds are greater than normals' in spite of the height of blinds are inferior to normals' so it seems that blinds have shorter legs than normals. (3) Kaup's index of blinds are inferior to normals'. (4) The girth of the upper arm of blinds are greater than normals' at the young ages, but the elder ages in school-life are inferior to normals.