No. 4. Rain or distilled water, one gallon; bromine, one and a half drachm; sulphuric acid, two and a half drachms; hydrochloric acid,[C] two drachms.—Shake well as each is added in the above order.
[C] This acid dissolves glass with great rapidity. It is purchased in leaden bottles. A single drop on the skin would make a sore difficult to heal. Daguerreotypists should bear in mind that the accelerating chemicals used in the Daguerreian art, are of the most volatile substance, and more difficult to experiment with than all other in the range of chemical science. When hydrofluoric acid is to be measured, the graduated glass should be partly filled with the mixture to which you intend adding it.
Use. To one ounce water, add from fifteen to thirty drops quick; coat over an incipient rose; over quick, nearly change the color to fair rose; recoat about one-third or one-fourth as long as at first coating. The coating box should be charged strong enough to change the plate in from one to four seconds. One advantage this mixture possesses, it will work in one-half the time required for any of the foregoing combinations. One very serious objection to its use is, it cannot, without great care, be made to work with certainty; and another objection is, it will not last long, as the box will require to be replenished after having coated from eight to fourteen plates. The older, however, this mixture is, the more certain in its operation. We have one gallon which has been made two years.
No. 5. Dry Quick. We have already given this preparation in a former number of this Journal.
No. 6. Acidulated Quick. Water, one pint: bromine, ten drops; chloride of iodine, forty drops; nitro-muriatic acid, one-fourth ounce; sulphuric acid, two drops.
Use. One part quick to ten parts water; coat over iodine to orange; over quick to rose red; recoat one-fourth.
There are thousands of different combinations and agents employed, and, after all, let every Daguerreian make up his mind to first become acquainted with some good combination of bromine and iodine, there will be less complaining of Quicks.
Money received since our last Number.