(7)試管普通的試管(圖五),是上下口徑相等,一端封閉的玻璃管。它的尺寸大小不等,最常用的有六吋長,口頸約十五毫米。在一般的實驗中,為了明瞭物質的性質,或檢查一般物質的化學成分,以期得到初步的瞭解和認識時,常要用它,因為它的容量 (7) Test tube An ordinary test tube (figure 5) is a glass tube with equal upper and lower calibers and one end closed. It varies in size, the most common being six inches long and about fifteen millimeters in mouth and neck. In general experiments, in order to understand the nature of a substance, or to examine the chemical composition of a general substance, in order to obtain a preliminary understanding and understanding, it is often used because of its capacity.