This is a preliminary report of the application of several methods in the making of bamboo pulp. The two-stage soda process and the two-stage sulfate process were first tested. It was found that the pulp obtained by the second process can be better bleached than that by the first process. In order to im-prove the quality of the pulp, the three-stage sulfate process was then applied. It consists of three steps, namely, cooking in water under slight pressure (115℃) for about one hour, digesting in a solution of one percent of the cook-ing reagent (HaOH:Na2S=2:l) at 120℃ for two hours, and finally digesting in a 5% solution of the reagent for three hours. This 3-stage method gave a product which is satisfactorily white and was found equally applicable to sev-eral kinds of bamboo used. The optimum operating conditions of the third stage of the 3-stage sulfate process was studied. The experimental results show the most suitable condi-tions as follows: Temperature-160℃, concentration of the digesting solution -5% (NaOH:Na2S=2:l), and time of digestion-31/2 hours. The pulp ob-tained under these conditions was white and the consumption of the bleaching reagent was relatively low. The surface layer and the core of bamboo were separately treated with the 3-stage sulfate process. The products obtained showed very little differ-ence in color and in the consumption of the bleaching reagent. This seems to indicate that the surface layer is not necessarily more resistant to bleaching re-agent. Only three kinds of bamboo have been employed in the present study. It is certainly inconclusive whether the 3-stage sulfate process used and the op-timum operating conditions determined are equally applicable to all other kinds of bamboo in our country. This is evidently the direction of further study.

1. A simple method is presented for determining double bond index of pure unsaturated hydrocarbons, petroleum fractions and other hydrocarbon mixtures based on a correlation of observed refractive index, calculated refrac-tive index, molecular weight and the number of double bonds per molecule. The data neccessary are: (a) mid-boiling point, (b) refractive index at 20℃ for sodium D line, (c) density at 20℃ and (d) weight percent hydrogen of the sample. 2. The double bond index determined by the present method for pure unsaturated hydrocarbons and unsaturated concentrate from petroleum fractions agree fairly well with that determined by Lipkin, Sankin, and Martins method, but there is some discrepancy for petroleum fractions containing saturated hy-drocarbons. 3. For identifying the predominant type of aromatic or olefinic hydrocar-bons in a petroleum fraction, the double bond index should be determined on unsaturated concentrate when the present method is used.

A generalized equation, is derived to calculate the molal latent heat of vaporization, λ, of any substance at any reduced tem-perature, Tr , and reduced pressure, pr, with an error generally less than 5%.