Sentence:  The ratio between <WSD>spissitude</WSD> and percentage strength of solution varies, however, with the temperature, as shown by Figure 7, higher temperatures showing less increase in <WSD>spissitude</WSD> with increasing percentage strengths than is the case with low temperatures. 
Meaning of the word marked with <WSD> tags:  Density, thickness; the state or quality of being inspissated or thickened.