In Dr. Diamond's directions for the calotype, he gave a formula for the addition of bromide of potassium to the iodide of potassium, but did not speak with much certainty as to the proportions. Will he kindly say whether he has made farther trials; and if so, whether they confirm the proportions given by him, or have led him to adopt any change in this respect? and will he likewise say whether the iodizing solution which he recommends for Turner's paper, is suitable also to Whatman's?
In albumenizing paper, I have not found it desirable to remove the paper very slowly from the solution. Whenever I have done so, it has invariably dried with waves and streaks, which quite spoiled the sheet. A steady motion, neither too slow nor too quick, I have found succeed perfectly, so that I now never spoil a sheet. I have used the solution with less albumen than recommended by Dr. Diamond. My formula has been.—
Albumen 8 oz.
Water 12 oz.
Muriate ammon. 60 grs.
Common salt 60 grs.
And this, I find, gives a sufficient gloss to the paper; but that of course is a matter of taste.
I have not either found it essential to allow the paper to remain on the solution three minutes or longer, as recommended by Dr. Diamond. With Canson paper, either negative or positive, a minute and a half has been sufficient. I have used two dishes, and as soon as a sheet was removed, drained, and replaced, I have taken the sheet from the other dish. In this way I found that each sheet lay on the solution about one and a half minutes, and with the assistance of a person to hang and dry them (which I have done before a fire), I have prepared from forty to forty-five sheets in an hour, requiring of course to be ironed afterwards.
I have tried a solution of nitrate of silver of thirty grains to one ounce of distilled water, to excite this paper, and it appears to answer just as well as forty grains. I send you two small collodion views, takes by me and printed on albumenized paper prepared as mentioned, and excited with a 30-grain solution of nitrate of silver.
Is there any certain way of telling the right side of Canson paper, negative and positive? On the positive paper on one side, when held in a particular position towards the light, shaded bars may be observed; and on this side, when looked through, the name reads right. Is this the right or the wrong side?