SPECIFIC GRAVITY AND DISPLACEMENT OF SOME SALINE SOLUTIONS. 45 



As in the three series detailed in Table C the mean observed temperature is 

 identical with the standard temperature, 19 "50°, no temperature correction is required, 

 and the weight 37034 grams is that which is, in the first case, required to immerse 

 the hydrometer to the 50-mm. mark in the saline solution of 19-50°. 



Adding this weight to that of hydrometer No. 17 in vacuo, we get 180'9113 

 + 37034= 184'6147 grams, entered on line s ; this is the total weight of the hydro- 

 meter when floating at the 50-mm. mark in the solution under experiment. 



Dividing this number by the displacement of the hydrometer when floating at the 

 50-mm. mark in distilled water of the same temperature, 19'5° C, namely, 18r7105 

 grams, line s', Table C, we obtain 1 '01 5982 as the specific gravity of the solution. 

 The specific gravity calculated from each series of observations is given at the foot of 

 the corresponding column, in line t. 



Table C. 



Hydrometer No. 17. 



Details of the Determination of the Total Weight of the Hpdrometer when floating 

 at the 50-m?>i. mark in a solution of ^ gram-molecule of Ccesium Chloride in 

 1000 grams of water at 19*50° C, and the Specific Gravity of the Solution. 



Particulars of hydrometer, . 



a 



Hyd. No. 17. 



J. Y. B., 1893 



Weight in vacuo 



= 180-9113 grms. 



Reference to laboratory note-books, 



b 





XX. 79 



XX. 87 



XX. 91 



Date of experiment, .... 



c 





April 22, 190i 



April 22, 1904 



April 22, 1904 



Time at start, ..... 



d 





2.00 p.m. 



3.18 p.m. 



3.50 p.m. 



Temperature at start. 



t 





19-50° 



19-50° 



19-50° 



Added weight, w, and reading, R, 



/o 



w 



R 



R 



R 



First added weight or reading, R, 



/l 



3-3 



6-0 



5-5 



5-5 



Second 



f1 



3-4 



16-5 



16-5 



16-5 



Third 





h 



3-5 



28-0 



27-5 



27-5 



Fourth 





A 



3-6 



38-5 



38-3 



38-5 



Fifth 





h 



3-7 



49-8 



49-5 



49-5 



Sixth 





U 



3-8 



60-5 



60-3 



60-3 



Seventh ,, ,, , 





fi 



3-9 



71-3 



71-1 



71-1 



Eighth „ 





fs 



4-0 



82-5 



82-0 



82-5 



Ninth 





/o 



41 



93-5 



93-0 



93-5 



Mean added weight, w. 



9 



3-7 









Mean reading, R, . . . . 



h 





49-62 



49-30 



49-43 



Time at finish, ..... 



i 





2.15 p.m. 



3.35 p.m. 



4.05 p.m. 



Final temperature, .... 



J 





19-50° 



19-50° 



19-50° 



Mean temperature, T, ... 



k 





19-50° 



19-50° 



19-50° 



Range of temperature. 



I 





0-00 



0-00 



0-00 



Difference of mean reading from 50 



m 





0-38 



0-70 



0-57 



mm. (50-R = dr), 













Weight equivalent to displacement dr 



n 





0-0034 



00063 



0-0052 



{ = dwr), 













Weight required to immerse hydrometer 









3-7034 



3-7063 



3-7052 



to 50-mm. mark at mean temperature, 













T, {w + dio,), 













Difi'erence of mean temperature, T, 



P 



... 



000 



0-00 



0-00 



from standard temperature, T, (T - T 













= dt), 













Correction for difference dt ( = dwt), 



9 





0-00 



0-00 



0-00 



