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of the exposure must vary according to the strength of the acid [&?] copper requires stronger acid & a longer exposure than steel. My plates were exposed about 1 3/4 minutes. The best way is to test it on a spoiled plate each time. By pouring off the acid & stopping out the lights – very beautiful effects can be produced but I have not attempted this yet.
The priciple precautions are to spread the ground evenly and securely – it must be neither too hot nor to cold. I had a good many failures in spreading grounds; care must also be taken not to scratch the ground – or there will be some engraving on the plate not desired, and the acid should be watched carefully & not left [on?] too long. The burnisher, scraper & graver are useful in making alterations after the plate is etched. New grounds can be spread and additions made as often as necessary. Should you come to Davenport I can show you all the above much better than I can describe it - and in less time. It is the most satisfactory mode of illustration I know of. The whole outfit costs less than $5. The plates (8") cost about $15 per 1000 for paper & painting. I obtained the materials from the Franklin Bank Note Co., 107 Liberty St. new York.
It was a great pleasure to me to meet you & [Mr. Aslous?] in Des Moines – and – hope I may have the pleasure of meeting you more frequently hereafter.
Our subject that I would have liked to have [?] to you was about – is the matter of State Entomologist – The bill introduced by [?] is a copy of the Illinois laws of 1867 under which Mr. Walsh was appointed, but naming the Agr. Coll. as depository of the collections, I feel much interest in having this or some other bill as good or better go into effect. I lear from Mr. Riley that he would accept the position if it is offered to him -& the salary is reasonalbe – not less than $2000. I don't suppose there is any one in the U. S. better qualified for the position & I hope iowa will have the wisdom to make this appropriation (instead of the $50000 for grasshopper seed). Mr. Fosters bill was reported [sic.] back to the senate by the Agr. Comm. adversely - & has now been referred to the Agr. College Comm. where I hope it will undergo such changes, as will make it acceptable to the legislature to the Agr. Coll. to Mr. Riley. You know what is to be done to get it through better than I do - but if you can do anything more please let me know. I should like very much to learn your views upon this matter & will act with you to the best of my ability.
If you wish any further information about the [?] [?] position or better make us a visit in Davenport.
With best regards Truly your friend J. Duncan [Butnam?]
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Philadelphia, October 1st, 1880. Dear Sir: We desire to call your attention to our
NEW BOTANICAL SERIES,
consisting of 24 microscoping preparations (mostly double stained), illustrating the structure of the higher orders of plants. They are all neatly mounted on 3x1 slides, and will, we feel sure, be found valuable for private study as well as for class demonstration. The following is a list of the structures and cell contents shown:
1. Protoplasm and Nucleus in cells of Cypripedium pubescens 2. Simple Cellular Tissue, Parenchyma, in Stem of Elder 3. Parenchyma, Stellate form, in Rush, Juncus tennis 4. Woody Tissue in White Oak. Quercus alba, 2 sections. 5. Pitted Wood-cells, in White Pine. radial section 6. Annular Vessels in Impatiens fulva. 7. Spiral Vessels in Castor-oil plant. 8. Pitted Vessel in stem of Nerium Oleander 9. Scalariform Vessels in Fern, Osmunda. 10. Medullary Rays, in stem of Mahogany, 2 sections 11. Endogenous Stem, Smilax rotundifolia. 12. Laticiferous Tissue, in Leaf of Rhynospermium 13. Stomata, in Leaf of Cypripedium acaule. 14. Rootlet of Lemna, showing Root-cap, etc. 15. Stellate Hairs, on Leaf of Deutzia graeilis. 16. Stinging Hairs of Nettle, Urtica dioica. 17. Internal Hairs, in Water-lily, Nymphaea odorata 18. Glandular Hairs on Leaf of Sundew, Drosera. 19. Oil-gland, in cuticle of Lemon 20. Chlorophyll grains in Leaf of Moss, Hypnum. 21. Starch Grains, in Canna root. 22. Aleurone, Proteine grains, in Seed of Ricinus 23. Raphides, in Leaf of Fuchsia. 24. Cystoliths, in Leaf of Fieus elastica, section
Price, in neat polished Case, with four trays. $15.00.
Our stock of Optical, Mathematical and Philosophical Instruments is the largest and most varied to be found in the United States and is con stantly receiving accessions of improvements and novelties. Our complete Catalogue sent by mail, on application, as follows:
Part 1st, Mathematical Instruments, 160 pages. Part 2d, Optical Instruments. 188 " Part 3. Magic Lanterns, and Slides, 150 " Part 4th Philophical Instruments, 188 "
Respectfully Yours. JAMES W. QUEEN & CO., Opticians, 924 Chestnut Street, Philadelphia
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Philadelphia Nov 19 7 PM Pa.
Prof. C. E. Bessey Iowa Agr. College Ames Iowa
Philadelphia, October 1st, 1880.
Dear sir: We desire to call your attention to the
"English Mechanic & World of Science,"
an English periodical of great value, and one which is of universal interest to those interested in scientific matters. It is a weekly illustrated journal; each number containing twenty-four pages exclusive of advertisements, nine inches by thirteen; each page comprising three volumes. It numbers among its regular or occasional contributors many of the best-known names in science. We give below the table and contents of the first number which [comes?] to hand, namely, that of July 23rd, 1880.
Contents.
Articles [?] ... 461 [?] ... [?] [?] ... [?] [?] ... 464 [?] ... 465 [?] ... 465 [?] ... 466 [?] ... 466 [?] ... 466 Useful and Scientific Notes ... 467 Scientific News ... 467
Letters From [?] to [?]
Photograph of [?] [?], by Mr. S. Wells, ed. [?], U. S. A. —Powell and Lou [?]'s Newest Formula [?] Water [Thinner?] [?]—Inexpensive Microscopes, etc. ... 468
Microscopical—50,000 Diameters—Supposed [Chromatisation?] of Light by a Microscope Slide—[Chromatisation?] of Light by a [?] Plate—The Meteor of July 9th—Jupiter— Periscopic Eye-pieces—[?]—Carbonic Acid—[?]—Jupiter—57 [?]—[?] 469
Lunar Mists and Clouds—Lunar Rainbow [Column Break] [?]—Oxygen in the [?]—[?] [?]—[?] [?] [?] ... 470
Alphabetical Manual of [?] [?] Analysis —The [?] [?] [?]—The Trials of [?] Bankers upon the Lanceshire and Yorkshire [?]—Vapor [?] Water Analysis ... 471
A New Tricycle—Bicycle [?]—Monitoring Battery Plates—Aquarium—A [?] Air Pump ... 472
[?] and the [?] Purchase System—[?] [?] Machine [?]—[?]—"[?]" on [?]—How to Make a Violin 473
Impure Drinking Water—The Sanitary [?] [?]—[?] ... 474
Flight of Certain Sea [Birds?]—The Opaque Lanter ... 475
The Achromatic Object Glass—Physical Hypotheses —Animal [?] Vegetable ... 476
Improvements in [?] Burners—Light Theories, etc., etc.—[?] Engine—[?] [?] [?] [?]—A Candle Holder for Use with the Month [?] ... 477
Replies to Queries ... 478 Unanswered Queries ... 482 Queries From [?] to [?] ... 482 [Chess?] ... 482 Answers to Correspondents ... 484
The terms of subscription are very low, namely, for the United States, "13 shillings, or 3 dollars and 25 cents gold" (now equivalent to currency).
The following, from the English Mechanic, is self-explanatory:— "[?], James W. Queen & Co. of 924 Chestnut Street, Philadelphia, Pa., are authorized to receive [subscriptions?] for the United States for the English Mechanic, at the rate of Thirteen Shillings per annum, post free. The [?] will be forwarded direct by mail from the publishing office in London. All subscriptions will commence with the number first issued after the receipt of the subscription. If back numbers are required to complete volumes, they must be paid for at the rate of 4¢ each copy, to cover extra postage."
We consider the English Mechanic superior, [in point?] of reliability and general excellence, to any other journal of similar scope known to us–American or foreign. It contains much that is of special interest to Microscopists. Specimen copy will be sent on application.
Respectfully, James W. Queen & Co., Opticians, Philadelphia.
Our Complete Catalogue sent by mail, on application, as follows: Part 1st, Mathematical Instruments, 160 pages. Part 2d, Optical Instruments, 188 " Part 3d, Magic Lanterns and Slides, 150 " Part 4th, Philosophical Instruments, 188 "
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All Communications in reference to the business must be addressed to the firm
James W. Queen & Co. Mathematical, Optical & Philosophical Instruments.
924 Chestunut Street, Philadelphia, Philadelphia, [?] 19 1880
Prof. C. E. Bessey Dear Sir;
Your note of the [?] is at hand. Not having any complete sets on hand at this moment, we have requested Dr. J. J. M. [Angson?] of Fort Madison Iowa, who has one of these sets from us, to send it to you. We hope you will be pleased with it, as we have been to considerable trouble to get up a set of objects such as we thought suitable for illustration of structure, suitable both as regards subject and quality of preparation. After collecting considerable material for another
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party, and waiting a long time he failed us. The person who has now prepared them for us has done very well, but in some of these slides is not so successfull as we desire: we hope however that the new lot, which will probably contain some, (or perhaps all), preparations of another maker, will be much better. At any rate, we hope to improve, and would be very much pleased to receive any suggestion, wither as to suitable subjects or methods of preparation; for the [sic.] tissues we settled upon as being desirable to show, were selected by the writer without consultation with any experienced botanist.
Yours Very Truly Jas. W. Queen & Co. Dr. E. Pennock