TABLE I. (Hydroquinone). 
Cross- Ratio of the Ratio of the | Ratio of the 
Number of | section of blackening for blackening for blackening for 
the plate. the grain |ultra-red and mg. | yellow and m.g. « green and m.g. 
vs. Ag per 100c.m?. | Ag. per 100 cm? Ag per 100 c.m.2. 
10 A a == 05184 En 107156 a = 0.168 
0.55 | 
rop vat cn ee = 0.175 Fae = 0.152 me = 0.168 
1.787 1.483 1.636 
9A 656 0.187 Tice = 0.155 De 0.170 
0.56 | 
ede hep 1.483 1.602 1) 
| 
| 1.391 1.178 eer 
8A En 0.211 TI 0.178 En 0.192 
0.49 | 
1.4 1.191 [aes 
8B 6 = == 105223 6.32 7 0.188 =e == 05204 
| 
‚0.908 OET Id 4 0.869 _ 
7 A Ar 0.211 ETE 0.180 ade 0.202 
0.42 
‚0.943 0.781 0.880 
0.559 _ 0.491 — 0.547 
0.34 | 
„55 0. : 
6A ol = OL Doe ae OAT : = 0250 
| 0.361 0.307 _ 0.356 
5 A mee 0.212 a= 0.181 Dn 0.206 
0.28 | 
0.332 0.27 0. 
(GF Ws Di -05148 ~ | 0.188 _ 
4A 0.532 — 0.241 0.532 > 0.279 0.532 = 0.354 
LG an | | 
| “0126. v> POs | 0.183 
4B | oye 0.271 0.465 = 0.308 aa! 0.465 = 0.394 
| | | | 
0.0208 _ 0.0485 _ 0.0703 _ 
S.A | 0.205 =D S101 0.205 = 0.237 0.208 > 0.343 
oars | h 
| 0.0248 0.0547 0.0745 
3 B | ed ee a 
| 0.186 0.133 0.186 0.294 0.185 0.401 
| | | | 
| 0.0159 (0.0277 0.0364 
2A e= | = 0.2 ee == 
| 000 NE rn eee 
0.03 | | | 
| (0.0182 0.0307 0.0390 
ZB ee = == 
| 0-00 Cio 2 mm 
') The estimation of silver failed. 
