418 Scientific Intelligence. 
(improves, indeed, with age), and does not stain the negative, and that 
the silver is deposited i in a finer condition. 
(.) Mr. Simpson recommends the following formula: 
Green vitriol, . : : . 5 grammes. 
Tartaric acid, . . ; ‘ 2 aes: 
Water, ¢ E ‘ : oO re 
A mixture of — ale with nitrate of silver remains clear until full 
intensity is obta 
c.) I lens uses for developing the negative the usual iron de- 
veloper, and then adds to it, for intensifying, a small quantity of the 
following solution : 
Citric acid re r : 3 grammes. 
Whnata’ of silver, ‘ . : i 
Distilled water, . : s aaa i a ee 
—Le Moniteur de la Photographie, 3° Année, No. 9, p. 67. 
[We i used a formula similar to the last with the best results — 
SPs Oud 
(d.) To. these we may add the following pc mae from Mr. Liefert, a 
French photographer residing at San Francisco, of a developer which 
at once gives to negatives on a Se dadiced, Gedlodion all the intensity 
desired. Dissolve together 
vitriol, . . . 80 grammes. 
Porifed nitre, . ‘ : : Le es 
ater, ‘ x 420 . 
Add Acetic acid, No. 8, 3 80 d 
Alcohol at 32°, is : 
Silver bath at 10 p- ag - + oe 2 
—Le Moniteur.de la Photographie, 3° Année, No. 7, p. 4 
(e.) Mr. Charles Waldak recommends the following davai for 
positives on glass, the first seh een the whites dead, and the second 
making them brilliant and metallic 
For the dead whites. 
Green vitriol, . : ; é 5°30 grammes. 
W: ‘ ‘ S108 * 
Acetic acid, N oO. 8: é za $ 3 aa | Seats 
Alcohol, ‘ ‘ * : 500 se 
Pure nitre, . ‘ fe 4 : 3:00... °° 
For brilliant or metallic whites. 
Green vitriol, . = : 4-50 grammes. 
WwW . 8 . 85000 
Acetic acid, ‘No. 8, ‘ ‘ $7 
; ‘ ‘. 5: ™ 
Pure nitre, . ‘ ‘ a Me 
30 
75 
Solution of nitrate ~~ silver (ordinary bath), re 
Nitric acid, . 20 drops. 
secon, of soar, sts ee rapidly thn the fis. 
