Formula for Acid Baths.

(H. R. Blaney.)

No. 1shouldregistertoBeaumé'sscale 42 deg.
No. 2"""""37 deg.
No. 3"""""33 deg.
No. 4"""""30 deg.

The temperature of the bath to be at 63 deg. Fahr. when tested.

(Denison's.)

No. 1 should be made to register Beaumé's scale, 45 deg., the percentage of perchloride in this solution is 47, and the specific gravity 1.444.

No. 2, 40deg.;percentage,41;spec. grav. 1.375
No. 3, 38""38;"1.339
No. 4, 35""35;"1.313
No. 5, 27""27;"1.225

From an article in the Photographic News (English), Nov. 1, 1889, as practiced in India.