458 
MESSRS. T. B. THORPE AND J. W. RODGER OX THE RELATIOXS 
Isokeptane (Dimethyl-Butyl-Methane). (CH 3 ) 2 CH.( 0112 ) 3 . 0113 . 
Made for ns by Mr. W. A. 0. Rogers, Assoc. li.O.S., by Wurtz’s reaction. In its 
preparation pure inactive amyl alcohol was used; this was obtained by Pasteur’s 
method of fractional crystallization of the barium salts of amyl-sulphuric acid. The 
alcohol was converted partly into bromide and partly into iodide, and these were 
purified by fractional distillation before treatment with ethyl iodide or bromide and 
sodium. Tlie sodium, in thin slices, was gradually added to the mixed halogen 
compounds in a flask connected with a reflux condenser. The reaction was more 
vigorous in the case of the iodides than in that of the bromides. The contents of 
the flask were distilled over in an oil-bath and the distillate heated in sealed tubes 
with sodium to decompose any unaltered halogen compounds. The product was 
further purified by Just’s method (‘Annalen,’ 220, 154) and finally fractionally 
distilled in order to separate the diamyl simultaneously formed in the reaction. It 
boiled between 90°'35 and 90°'75. Bar. 76G'8 millims. Corrected and reduced 
b.p. = 90°-2. 
A determination of vapour density gave : Pound 49’47. Calculated 50‘00. 
The observations for viscosity gave :— 
Left limb. 
Right limb. 
Temp, 
Pl\ S.S. 
Corr. 
'/■ 
Temp. 
Press. 
Corr. 
0°41 
103-45 
-000043 
-004743 
0 44 
103-39 
■000043 
■004744 
7-69 
103 33 
-000046 
-004339 
7-71 
103-31 
■000046 
■004347 
J.5-92 
103-30 
-000050 
-003955 
15-85 
103-24 
-000050 
■003963 
24-66 
103-23 
-000054 
-003602 
24-61 
103-18 
■000054 
■003613 
32-32 
102-79 
-000058 
-003332 
32-30 
102-74 
■000058 
■003335 
40-06 
102-71 
-000062 
-003089 
40-05 
102-70 
■000062 
■003095 
49-03 
102 64 
-000066 
■002838 
49-00 
102-56 
■000066 
■002840 
56-47 
102-56 
-000070 
■002652 
56-45 
102-52 
■000069 
■002650 
63-91 
102-47 
-000073 
■002483 
63-93 
102-42 
■000073 
■002485 
71-82 
102-42 
-000077 
■002314 
71-86 
102 35 
■000077 
■002319 
80-65 
102-26 
-000082 
■002146 
80-66 
102-21 
■000082 
■002153 
88-39 
102-21 
-000086 
■002010 
88-43 
102-14 
■000086 
■002015 
In reducing the observations we have used d (07*1°) = 0'G969 for the density, and 
the expression 
V - 1 + -0012394^ + -07 19318^' + -0713058^3 
for the thermal expansion (Thorpe, loc. cit.). 
Taking = '004743 = '002012 ' (calculated) = '003089 
= 0°'42 i(g = 88°'41 L 2 (from curve) = 40°'07, 
we get 
362-79 
~ (180-47 + 0“ ’ 
