VENETIAN TURPENTINE METHOD 2 
on 
series of experiments the remainder of the conditions were the 
same. Volume of Hempel’s dessicator, 4200 cc; volume of crystal- 
lizing dishes, 2450 cc; amount of 10 per cent. Venetian Turpentine 
for each experiment, 25 cc; average free surface of the turpentine, 
16sq. cm; and average temperature, 25°C. The amount of drying 
agent in each case was determined by the molecular weight of 
substance, 880 gm. calcium chloride being taken, and in case of 
the other agents an amount relatively proportionate. 
These drying agents were not changed after each concentra- 
tion, but kept for the whole series to ascertain the relative falling 
off in value after concentrating a number of the solutions. In the 
tables, the Roman numerals signify the successive turpentine 
preparations placed in the drying vessel, all of the same volume at 
start and finish, and following each other immediately in point 
of time. The figures in each column mark the time required for 
each concentration. 
TaBLE No. I. (Dessicator, air-tight). 
Order of | ZnCl, and | Machanical mixture x Lee 
. Ayes 4 ; = AR Fused Fused 
Concen- |CaCl,fused| of ZnCl, and CaCl, igen Boe H,SO, 
tration | together fused separately ete — 
i | 24 hours 32 hours 25 hours | 41 hours | 32 hours 
ibrar A ad BG Geseeh LZ 3 fe ee AGs ee 
1 ol a 1 la Aor tii oe 44 
IVE Aol ae Agus: 
Mister dS bei. GU e tod, 
TapLE No. Il. (Dessicator not air-tight). 
Geel Fused ZnCl, Fused CaCl, H,SO, 
Concentration ee Wao : ies 
le 40 hours 58 hours | 37 hours 
ie ci a BG eae 1 
III. Arie ¥ Gauss: | 45 
IV. BO as | 
Se ee Se ee 
From the above data we can satisfactorily conclude that for 
all practical work in the Venetian Turpentine method, either 
zine chloride, or a mixture of zinc chloride and calcium chloride 
fused together, or a mechanical mixture of these two separately 
fused is better by far than calcium chloride. These three reagents 
have about the same drying powers, nearly equaling each other 
