Sentence:  Chlorophosphuret of nitrogen (at ordinary temperatures) is a solid crystalline body. ... The form of the crystals, as obtained by sublimation, is that of a rhomboid, of which the obtuse angle measures 131° or 132°, the <WSD>acute</WSD> 48° or 49°: the <WSD>acute</WSD> angle of this rhomboid, either at one or both ends, is often truncated, when of course the angle formed is about 114°: the hexagonal prism is also found. 
Meaning of the word marked with <WSD> tags:  Of an angle: less than 90 degrees.