10 . ROYAL SOCIETY OF CANADA 
The experiments were conducted in a room free from any artificial 
contamination from radioactive substances, and in carrying them out 
the cylinders were first carefully cleaned with glass paper and then 
thoroughly washed out with hydrochlorie acid, water, ammonia, and ethyl 
alcohol and finally before making the measurements, air filtered through 
glass and cotton wool was blown through each of them for fifteen or 
twenty minutes. The results obtained with the different metals ex- 
amined are contained in Table I. 







Table I. 
= wea SS 
Te) og OUMOIE 
3 | S845 SF Nee Sa REMARKS. 
HUP À =: AA EE S 4 © Ÿ 
E Berge ae | Sem? 
RS ON a0 Wl NE 
Z | aonAa | Ha | dose 
ai L SEE 
1 | Lead. | 1.85 | 23 This sample was taken from a sheet of 
| | lead which had been used as a lining in a 
case installed in the University over 
| twenty-eight years ago. 
2 | Lead. | 2.25 | 160 Commercial English sheet lead obtained 
| from the lead works at Toronto. 
3 | Lead. | (45 37 Commercial English ‘sheet lead selected 
| | from a different shipment from No. 2. 
4 | Lead. 1.85 | 78 This sample was obtained from a sheet 
| | rolled from an old pipe which had been 
| used as a drain for 25 or 30 years, and was 
| afterwards melted down. 
5 | Lead. 1 80 34 Rolled from a pig of lead recently re- 
ceived from the smelter at Trail, B.C., 
Canada. 
6 | Lead. ne SO re! 55 Rolled from English pig lead; Quirk 
| and Bartons. 
7 | Lead. eel 80 à 61 Rolled from English pig lead. Cook- 
| son's. 
8 | Zine. 1.62 15 Commercial sheet zine. 
9 | Aluminium. AL 15 Commercial sheet aluminium. 



From this table it will be seen that the values of “q” for 
aluminum and zine are somewhat less than those found by Eve for this 
constant with the same metals. They are, however, in good agreement 
with H. L. Cooke’s corrected value “q”—13.6 given by Eve for air 
confined in a well cleaned brass vessel. 
The values found for “q” in the experiments with lead cylinders, 
as will be seen from the table, range from 23 to 160 ions per cc. per 
