In making the quatitative spectrographical analysis of the impurities in aluminum and aluminum-oxide mentioned in this report, the writer used throughout a crystal spectrometer of the Qu-24 type made by The Zeiss of Germany and its accessories.A quantitative spectrographical analysis of aluminum is possible with a Feuessner spark generator (the connection diagram of which is described in the principal thesis) under the graphical conditions, viz., voltage: 12, 000v.; condencer capacity: 0.0066μF.; inductance: 0.8mH; spark gap: 2mm.; and the diameter of specimen: 3.8mm.It is usually the case that, in carring out the quantitative spectrographical analysis under consideration, several standard specimens are photographed on one and the same dry-Plate with an unknown specimen. However, in view of the fact that the blackening between the spectrums of aluminum is uniform on the same plate on the same graphical conditions, this analysis can be done without the use of any standard specimien, when and if one of said spectrums is specifically taken as corresponding to a certain percentage of impurity. This method will be specially dealt with in a concrete manner.In making a quantitative analysis of silica, ferrous oxide and sodium oxide contained in aluminum oxide, holes are made at both opposite ends of pare carbon electrodes, each having a diameter of about 5mm., and they are filled with alminum oxide suitably ground in an agate mortar and subjected to a spark generated with a Feuessner spark generator under the conditions, viz., voltage: 12, 000v.; condenser capacity: 0.006μF.; inductance: 0.08mH.; and the distance between the electrodes: 2mm. The percentage of the impure contents can be ascertained by spectrc-analyzing the light emanating from the po der, with which the holes are filled.