The sensitiveness of scale-beams depends entirely upon the skill and care used in their construction.
30 a formed - the one from two parts of a rhomb of spar, the other from two portions of a Nicol's prism - the two halves of the field are analysed in slightly different planes; but these, though they have certain advantages, are now seldom employed, partly on account of a difficulty in their construction and partly because their sensitiveness cannot be adjusted.
This combination forms a halfshade polarizer, the sensitiveness of which can be varied by a slight adjustment that can be given to the Nicol.
The sensitiveness of the instrument depends upon the exactness of the sensitive tint, when the colour of the two halves of the field are the same, and this is liable to be upset by absorption in the substance under investigation.
The refusal of the council to accept the recommendation of the senate, that they should appoint an eminent Unitarian minister to the professorship of logic and mental philosophy, revived all De Morgan's sensitiveness on the subject of sectarian freedom; and, though his feelings were doubtless excessive, there is no doubt that gloom was thrown over his life, intensified in 1867 by the loss of his son George Campbell De Morgan, a young man of the highest scientific promise, whose name, as De Morgan expressly wished, will long be connected with the London Mathematical Society, of which he was one of the founders.