454 Royal Society : — 



3rd. It seems the best arraugement, to have the narrow tube of 

 flat bore, not too flat ; its greatest width being about equal to the 

 diameter of the wide bore, which should be cyluidrical, and neither 

 conical nor flat. 



4th. The tubes should be well deprived of air before being sealed. 

 The instrument may be thus graduated. 



If, when held vertically, the smaller tube being below, the mer- 

 cury at the ordinary temperature should fill the lower tube, the bulb 

 and part of the upper tube, the instrument may be pomted ofi" in 

 the same manner as an ordinary thermometer. But, if the mercury 

 under these circumstances be not enough to fill the bulb, the best 

 plan is perhaps to lay the instrument horizontally in a vessel of 

 water, side by side with a standard thermometer, and, keeping the 

 extremity of the mercury in the one tube at a constant point, to 

 mark off' its extremity in the other tube at two or more diff'erent 

 temperatures, as shown by the standard thermometer. The length 

 of this tube corresponding to a degree may be then found in the 

 usual way. 



The same process may be followed with the other tube. Or, 

 take two points in the first tube — say A. and B, the distance between 

 them being, say 50°. Set the mercury at the point A, and mark oft' 

 its other extremity in the second tube. Set it now at the point B, 

 and mark its extremity in the second tube. The distance between 

 these two points in the second tube will be the length corresponding 

 to 50°. 



Graduate the tubes to within a short distance of the bulb, and the 

 best plan is perhaps to number the degrees from one extremity of 

 the instrument, beginning 0...10...20, &c., on to the mark on that 

 side nearest the bulb. Suppose this mark is numbered 100°; then 

 number the mark nearest the bulb on the other side also 100°, and 

 go on upwards numbering 110°, 120°, 130°, &'c., until reaching the 

 other extremity of the instrument. In the next place ascertain the 

 temperature of the mercury when it fills the bul'j and reaches only 

 to the nearest mark on both sides. 



Let this be C°. In taking an observation, note the numbers at 

 both extremities of the mercury, and deduct the less from the greater. 

 To the jiositive remainder add the constant C ivith its ^iroper sign, 

 and the sum vnll give the true temperature. 



" Electro-Physiological Researches." — Tenth Series. Part I. By 

 Signor Carlo Matteucci, Professor in the University of Pisa. 



In the first section of this part of his Memoir, Professor Matteucci 

 treats of the heat developed by muscles during contraction. Ad- 

 verting to earlier experiments by other inquirers, in which a rise of 

 temperature was observed to take place in the contracting muscle 

 while the blood still continued to circulate through it, and where, 

 consequently, it remained uncertain how far the efi'ect might not be 

 due to a modification of the circulation, the author describes his own 

 experiments, by which it is shown that the muscles of frogs, after all 

 circulation of the blood has ceased, aud by the sole act of contraction, 



