The first part of the work consists of thiamine analysis of 5 allotments of rice samples bought from retail shops in various districts in Canton from the end of 1954 to the beginning of 1957. Usually seven grades of rice are available, and the grades differ both in variety and extraction rate.It is found that the thiamine content of rice bought at the same time, or of the same grade bought within a few months may vary considerably. Two-third of the samples contain 0.11 to 0.18 mg of thiamine per 100 g of rice but it takes the range of 0.05 to 0.27 mg per 100 g to cover all the samples. With the exception of the lowest grade, the thiamine content in general increases with the lowering of grade and decrease of price.The second part of the work studies the influence of variety and of extraction rate upon the thiamine, niacin, riboflavin and protein content of rice. Seven varieties of rice commonly used for the seven grades extracted at different rates are obtained from a local rice mill by special arrangement with the City Food Bureau. 'Results show that milling decreases the content of these 3 vitamins and of protein, the decrease for thiamine and niacin being greater than for the other two nutrients. However, not only the original content of these nutrients in husked rice may vary, but also their degree of loss in milling may differ. Of the varieties studied the lowest grade of husked rice contains the greatest amounts of all the four nutrients while the "Super Grade A" tends to lose the least during milling. As a result, the milled products of these two varieties tend to contain slightly larger quantities of these nutrients.

In part Ⅱ, are presented the results of the physical measurements, which include standing height, body weight, shoulder width and grip strength, made on children of middle school and children's homes. Pelidisi index is calculated by using Pirquet's formula. In tables 1 to 6 are tabulated the average results of boys and girls of ages from 12 to 18 years old. Since the results of children's homes differ from those of the middle schools, they are tabulated separately. The differences in standing height and body weight of these two groups of children are shown in figures 1 and 2. The children from the Homes are considerably shorter and lighter than school children of the some age range. The boys tend also to be narrower in shoulder width.Compared with the physical measurements of the children of Shenyang in the northeast China, the Cantonese children are slightly taller and heavier at the beginning of this age range but the children of the Northeast grow at a slightly more rapid rate, so that at 18 years of age, they are about 2 cm taller, with approximately the same body weight.Hand grip measurements show that girls have only 2/3 the grip strength of boys. Values of Pelidisi are calculated for a]l the children. It is found that this index does not proper]y represent the nutritional status of the children of Canton. By all the other indices of the state of nutrition used in this survey, the school children are rated as having a higher nutritional status, than those of the children's home, while the Pelidisi ratcs them lower.Nutrition is considered to be one of the factors which causes differences in the growth and development of the various groups of children compared.

Thirty-six middle schools' boys, 14 to 19 years of age are selected as subjects. Most of them have been previously found to show symptoms associated with riboflavin deficiency. Their riboflavin intake is calculated to be about 0.4 mg per person per day.A one-hour urine sample is collected at S a. m. Immediately after collection, the boys are subjected to a 2 mg riboflavin loading test administered orally. Hourly urine samples' are collected for the four hours directly following the intake.The subjects are divided into 4 groups with 8 to 10 students in each group. Each student in group I is given orally a daily riboflavin supplement of 0.5 mg; group II, 1.0 mg; group III, 1.5 mg; and group IV receives no riboflavin supplement, but ointment treatment for scrotal dermatitis is applied. The procedure is carried out for a period of 14 days. The boys eat the ordinary school food and participate in the usual school activities.At the end of the 14-day period, a 1-hour urine sample is again collected. Another 2 mg loading test is performed, hourly urine samples being collected for 4 hours. All the urine samples are preserved with glacial acetic acid and toluene and stored in an electric refrigerator. The Lactobacillus casei method is used for the analysis of riboflavin.The results of the one-hour urine riboflavin analysis agree well with the dietary survey, showing very low values before the supplement, averaging 1.4 micrograms for the hour. After the administration of the supplement for two weeks, the riboflavin content in the one-hour urine samples increases stepwise with the increase in supplement, the highest being 11.4 for the 1.5 mg supplemented group. No increase is observed in the group IV using ointments.The 4-hourly urinary riboflavin excretion following the administration of the 2 mg load averages over per cent before the supplement and increases to 11.5, 15.6 and 17.8 per cent for the 0.5, 1.0 and 1.5 mg supplemented groups respectively. The curves in Fig. 1 show the hourly excretion of the 3 groups before and after supplementation.Clinical observations show that supplementation of 1 mg or more relieves some of the deficiency symptoms.It is suggested that in addition to the daily intake of about 0.4 mg 時iboflavin in the diet, 1.5 mg more should be added to keep the middle school boys in optimal riboflavin nutrition.

This study is undertaken simultaneously with the experiments for the determination of riboflavin requirement of middle school boys in Canton. The same subjects serve in both experiments. When the loading tests are performed, 2.0 mg of thiamine is given orally at the same time the riboflavin is administered. Supplements of 0.5, 1.0 and 1.5 mg thiamine are given at the same time and in the same order as the ribofiavin. The same urine samples are analyzed for thiamine as well as riboflavin. Thiamine is analyzed by the thiochrome method of Consolazio.The thiamine content in the one-hour urine samples of the subjects before the supplement averages 5.4 to 8.9 micrograms for the 4 groups. After supplementation, the thiamine content of the fasting samples of 1.0 and 1.5 mg supplement groups show definite increase, while the other two groups remain near the same levels.After the loading test, the 4-hour total excretion amounts to about 5 per cent of the 2 mg taken, with almost no difference among the groups. When the intake of thiamine has been supplemented for two weeks, the response to the loading test varies. The 0.5 mg supplemented group excreted 4.35% of 2 mg in 4 hours, while the 1.0 and the 1.5 mg groups excreted about 8%. The hourly excretions are shown in Fig. 1. The peak of excretion of the 1.5 mg supplemented group changes from the second to the first hour after the load test. The thiamine intake of these subjects is estimated to be about 1 mg daily. They are free from symptoms associated with thiamine deficiency and their 1-hour urine samples show that the quantity excreted may be within the range considered normal for healthy subjects, yet supplementation of 1.0 or 1.5 mg of thiamine is able to cause a greater and faster urinary excretion of thiamine. An additional intake of at least 1.0-1.5 mg thiamine to their ordinary dietary intake of about 1 mg may be desirable to ensure an optimum status of thiamine nutrition in the middle school boys.