between Viscosity and Density in Fluids. 53 



produced by discharging carbonic acid. After the mercury 

 had been thereby raised in the measuring-tube, the spaces A 

 and B were again put into communication. From the time 

 occupied by the mercury in the measuring-tube in descend- 

 ing from one mark to another, the coefficient of friction was 

 calculated by means of the constants of the apparatus. 



Three capillaries were employed, from 6 to 7 centim. in 

 length, and of which the radii amounted to 0*005162, 0-003601, 

 and 0*002847 centim. The validity of Poiseuille's law was 

 controlled ; but an equation cannot be deduced from the expe- 

 riments. 



The results obtained are contained in the following Table, 

 in which t denotes the temperature measured by the air-ther- 

 mometer, s and fi the density and the friction-coefficient in 

 the gramme-centimetre-second system, and p the pressure in 

 the measure above-mentioned; A, is the air-content of the sub- 

 stance, in parts of a volume, as given by analysis. The den- 

 sity of the liquid carbonic acid is taken from Andreef's expe- 

 riments*. 



s. 



t =32°-6. 

 X=000074. 



t =40°-3. 

 X =0-00085. 



P- 



/t . 10 s . 



p. /*.10°. 



o-soo 



0-730 

 0-660 

 0-590 

 0-520 

 0-450 

 0-380 

 0-310 

 0-240 

 0-170 



o-ioo 



107-3 

 88-5 

 80-7 

 78-2 

 77-6 

 77-2 

 76-6 

 74-6 

 69-9 

 60-3 

 43-1 



677 

 574 

 493 

 414 

 351 

 304 

 270 

 239 

 213 

 188 



114-6 

 101-6 

 94-9 

 91-7 

 89-2 

 86-8 

 82-7 

 75-9 

 64-3 

 45-3 



580 

 499 

 426 

 366 

 316 

 275 

 243 

 218 

 196 

 180 





t=25°-l 







X = 000044. 





P- 



s. 



ju.10 6 



105 



0-896 



800 



95 



0-875 



741 



85 



0-858 



703 



75 



0-827 



665 



70 



0-809 



628 



Annalen der Chetnie imd Pharmacie, 1859, ex. p. 1, 



