194 Answers to Quertes. 
form. I have just had my condenser lens mounted this way for 
another instrument, and so far as I can see it works well. The 
price of these condensers is for Zeiss’ stands 55/-; for the 
English stand to fit in the substage 65/-; and Baker’s simple form 
of mounting £2 to £3. For further information I must refer 
B. R. F. either to Carl Zeiss, Jena, or to his London agent, Mr. 
C. Baker, 244 High Holborn, London. J. G. P. VEREKER. 
402.—Odontomes.—I believe Canada balsam or dammar, if 
used nearly hard, as in the manner for bone and teeth sections, is 
the best medium in which to mount odontomes and also feetal 
skin. Vine 
407.—Rule Wanted.—There can be no rule for answering such 
a question as that put by “ Puzzled.” There may be, perhaps, a 
hundred different ways in which a sum of money such as £167 
odd could be made up of 1,604 coins, etc. For example, take 
some florins, shillings, and sixpences. There are six different 
ways in which a guinea could be paid in 21 coins, using some of 
each :— 
Florins. Shillings. Sixpences. 
I 23 18 445 2 
2 15 ee 4 
3 ah 12 as 6 
4 din 9 ane 8 
5 nee 6 ee 10 
OV 
oe 3 io 12 
If a guinea has six different ways of being made up, the probabi- 
lity is that £167 could be paid away in a still greater number of 
ways. The only method of solving such puzzles is by the ‘ ten- 
tative ” process, vulgarly known as the “rule of thumb.” M.A. I. 
407.—Rule Wanted. 
PENCE. Al B | C8) Dp | Ee Fe) en ae 
1200— ott er) cele eell. Lal ceeleeelees a u 
1175 
eed bee 1 serleee eee 
240 ve | 4 Saou cen bacon P| 13 
120-—|—|— cee [eee | Ge deee | eee P cee face [EQ]eee] ef 19) 
1 
60—|—|—|— vse | ae | Seu ge Woe |) ce wine Ra) 22 cr eee 
30—|—|— | |— = Scalia 24| 24 
24— I)... BS BBS 
I2—— is 205 |code 215 
OS acl poms 195 95 
1 
3—-— — — Bere PeaulnS || oy etre :<- (95 lesa MS 
a a a D4 J ocee | vee Jove | 5 5 
