SPECIFIC GRAVITY AND DISPLACEMENT OF SOME SALINE SOLUTIONS. 33 



Deter- 

 mination 

 No. 



Date. 



Mean Weight 



of Hydro- 

 meter in Air. 



Grams. 



Number 



of 

 Weigh- 

 ings in 

 Air. 



Barometer. 



Thermometer. 



Dry 

 Bulb. 



Wet 

 Bulb. 



Vapour 

 Pressure. 



Milli- 

 metres. 



Weight 



of 1 litre 



of this 



Air. 



Grams. 



Exact net 

 Buoyancy. 



Grams. 



Exact Weight 

 in vacuo of 

 Hydrometer. 



Grams. 



Hydrometer No. 17. 



1 



2 

 3 



5/3/1894 



24/4/1894 



2/6/1894 



180-7138 

 180-7165 

 180-7175 



4 

 4 

 4 



740-86 

 740-46 

 747-01 



6° 15 

 10-50 

 1390 



5"l0 



8-90 



11-50 



6-03 



7-70 

 8-89 



1-2288 

 1-2081 

 1-2037 



0-1979 

 1944 

 0-1938 



Mean = 



180-9117 

 180-9109 

 1809113 





180-9113 



Hydrometer No. 21. 



24/11/1893 i 187-5771 



5/12/1893 I 187-5764 



27/ 4/1894 I 187-5809 



4 

 4 

 4 



74905 

 7r)5-40 

 74365 



8-25 



9-85 



13-40 



6-70 



800 



1105 



6-56 

 7-07 

 8-65 



1-2327 

 1-2361 

 1-2006 



0-2060 

 0206ti 

 0-2006 



Mean = 



187-7831 

 187-7830 

 187-7815 



187-7825 



Hydrometer No, 3. 



9/3/1894 



10/5/1894 



2/6/1894 



178-1785 



4 



731-36 



9°-45 



7-70 



6-98 



1-1982 



0-1904 



178-1786 



4 



740-20 



14-10 



10-75 



7-97 



1-1924 



0-1895 



178-1776 



4 



746-89 



13-95 



11-50 



8-87 



1-2032 



0-1912 

 Mean = 



178-3689 

 178-3681 

 178-3688 



178-3686 



No. 17. 

 Final weight in vacuo accepted for each hydrometer, 180'91] 3 grams. 



No. 21. No. 3. 



187-7825 grams. 178-3686 grams. 



§ 14. As the displacement in distilled water figures in all the determinations of 

 density, we begin by making a number of series of observations of the displacement 

 of the hydrometer in it at the standard temperature chosen. 



We take as an example the case of hydrometer No. 17 in distilled water of 1 5 "00° C. 

 as it is given in Table A^. 



Table A-y. — This table gives in detail the data from which is derived the total 

 weight displaced by hydrometer No. 17 when floating at the 50-mm. mark in distilled 

 water at 15*00° C. Each line in the table is distinguished by a letter — a, b, c, etc. 

 In line a we have the number and particulars of the hydrometer used. In line b 

 is given a reference to the laboratory note-book in which the original observations 

 were entered, followed by the date of the experiment, line c. Lines d and i give 



TRANS. ROY. SCO. EDIN., VOL. XLIX., PART L.(NO. 1). 5 



