OF DILUTE ALCOHOLIC SOLUTIONS. 



capillary tube hc^ 12 cm. ; diameter of the capillary, 

 0.0544 cm. ; volume of the upper bulb between the 

 marks a and h, 6.51 c.c. The total volume of 

 liquid used was 9 c.c. 



After the fixed volume (=9 c.c.) of the solu- 

 tion had been poured in at e by means of a 

 pipette, the apparatus was sunk vertically under 

 the water of the thermostat until the mark a was 

 a sufficient distance below the surface. The liquid 

 in the bulb d was pushed up, by pressing in some 

 dry air at e, and when its head reached the mark 

 a, the pressure was removed and the liquid was left to flow 

 down the capillary by its own weight. The time required to 

 flow down from a to ^ was then read. 



The time was measured by means of a watch, capable of 

 being read to one fifth of a second. 



As is well known, when t and i! are the times of flow from 

 a to hi and s and s' are the densities of any two liquids re- 

 spectively, then the ratio of their absolute viscosities y^ and r/ is, 



r/ _ s'.t' 



Hence if we know the time of flow and the density of a liquid 

 we can readily calculate the specific viscosity of that liquid. I 

 measured the specific gravity of a liquid with a Speengel's 

 U-shaped Pyknometer whose capacity was about 3 c.c. 



At first, I made the determinations with solutions having 

 only one dissolved substance. 



I found that the formula (2) gives good results, in a wide 

 range of concentrations, with the dissolved substances I had 

 taken, except in the case of water ; the following table gives 



