F. D., of N. Y.-We are much obliged for your letter. The party to whom we referred is not the one named by you. W. P., of C. W.-We do not know where you can procure, in this country, machinery for fence-making. J. H. C., of Ohio.—The party to whom you refer cannot. by the re-issue of his patent, and the alteration of hid claim, deprive you of tyonr right to whatever was origInally assigned to you. The object of a re-issue is to correct 'some error discovered since the issue of the patent, and therefore your rig hts are cfot impaired by such reissue. R. L. S., of N. Y.,enquires if we know of any mcthods of connecting the wires of the telegraph with the earth by means of a connecting wire for the purpose of preventing damage being done to the poles by lightning. Answer :—We do not know of any conducting substance whichcaD make that nice distinction neces-Barytocarry off lightning.without taking thecurrent of elcctricity from the battery with it. If Mr. S. has got a metal that can discriminate on so nice a point, he has got a little beyond our scientific acumen. W. W., Jr., of Mass.—The blue color you observed on the bottle containing sulphate of quinine is due to that substance, for it possesses the power of polarizing light. J. J. Heron, of Sunbury, Ohio, wishes to correspond with the manufacturers of the best horizontal shaft water wheels for saw mills. G. F. D., of Ga.—Messra. T. J. Aldrich, of Jersey City, N. J., will answer your inquiry concerning their patent steam generator, if you address them. Tred-gold's work on the steam engine will answer your purpo,e. D.Appleton Co., book publishers, this city, can furnish it. C. P. H., of P".— Aidre33 Anthony Pierz, of this city, for inf orma :on relative to making a fertilizer out of leather scraps. J. A. S., of Minn.—The substitution of a cam for a crank for giving motion to a mill saw is an old idea, and consequently not patentable. I. H., of Conn.—G. H. Waoi, of Green Bay, Wis. has a good rock-drilling machine, which he has secured by Letters Patent in this country and abroad. J. C., of N. J.—The excess of soap, alkali or grease used in cleansing cloth has often been used over again; but it is no actual saving. At an early opportunity we will write on the subject you mention. O. V. F. of Ohio.—We do not believe it po,sible to impregnate dough or paste with atmospheric, air sufficiently to cause the same to rise and expand when exposed to heat, and occupy four or five times the space of its original bulk, as required to produce healthy bread. It is a well-known fact that water will absorb its own bulk of carbonic acid gas, however dense it may be rendered by pressure, and by mixing the dough with water thus impregnated while under pressure, according to Dauglish's process, it is diffused throughout aU its parts, and when relieved of its pressure the gas leaves it. and in so doing expands the dough into-A beautiful spongy and elastic mass. Constructing bottoms of chairs of tin, zinc, or sheet iron, in the manner you propose, is not new. B. S., of Me.—We shall be happy to receive practical and uscful information from you, regarding the manufacture and application of iron girders. J. L.. of Va.—The material you sent us is a micaceous sand, and does not appear to contain any silver. If you have good reasons for thinking it does, from the geology of your district, send to an analytical chemist and get a Bpecimen examined. E. H., of Mass.—The patent to which you refer is now in the hands of a ctnnpany here, with prospects of good success. It was sold in Englandfor a very large sum— report says $100,000. W, M. F., of N. J.—We do nofknow where you can obtain the metal aluminum for dental purposes. H. E. G., of Ill.—We do not know where you can ob_ tain left hand auger bits for boring in a reverse direction to the ordinary bit. The best metal to be used for journal boxes liable to heat, is that known as the Babbitt metal, the receipt for which recently appeared in our columns. H. R.. of Iowa.—Rice is made to imitate peari by boiling it to the consistency of paste, and subjecting it to a strong pressure between -surfaces indented with angular or prismatic ridges. for extracting the aqueous matter from, and solidifying, the substance, and giving it such prismatiC ridges on its sudace as will decompose the light, and give the peculiar pearl-like hue to it. If there is anything new in the construction of any part of the affair you contemplate forming of iron, it can be patented. B. L., of N. Y.—If you assigned one-half of your interest in your patent to a party, and a part of the conBideration was to the effect that the purchaser should devote his time to the introduction of the invention, and he fails to do so, your only romedy is to sue him for violating his contract. You cannot get the assignment revoked. Money received at the Scientific American Office on account of Patent Office bUSiness, for the weekending Saturday, May 22,1858 :— H. D. W. of Mich., $25 ; J. H. N., of Iowa, $55"; E. B. W., of N. C., $25 ; S. P., of Mass., $25; D. J. e, of WiB., $30; W.N. W., of Ohio, $30; B. B:S., of Mass., $30; J. C. F., of Texas, $35; M. G. B., of Tenn., $30; D. S. M., of N. Y., $55; D. Y. C., of Pa., $25; W. H., ? of Ohio, $25; E. J., of Conn., $27; H. L. A., of Wis. J $30 ; A. D., of N. C., $50; A. J. C, of Tenn., $30; A. J F.,ofN. J.,$30(J. 0., of Pa., $5; G. W. R. S., of Va., 'V$25; P. r. L., of Ala., $41; M. C. C, of N. Y., $30; L. gA. G., of Mass" $30; T. G. Y., of N. Y., $30; O.D.W. ofN. Y., $30; T. E. P., of-----,$55; J.M., ofN. J., $25 ; F. B. N., of N. Y., $30 ; J. A. B., of Fla., $20; S. G., of N. Y., $25 ; E. S., of La., $60 ; W. G., Jr., of N. Y.,$100; Z. C., of Ill., $80; G. H.,of Conn., $30; K. B., of N. Y., $20 ; M. M. S., of Ill. $25; H. H. L., of R. I., $25 ; T. - S., of Pa., $25; E. B. of Mo., $30: H. S., of N. Y.,$55; W.B.of N. J.,$20; J.T., ofN. H., $30; G. W. C., of Wis., $25. Specifications and drawings belonging to parties with the following initials have been forwarded to the Patent Office during the week ending Saturday, May 22, 1858 :— J. C. B., of N. Y.; E. J., of Conn. ; F. J. G., of N. c.; T. W., Jr., of Conn.j D. Y. C., of Pa.: W. H., of Ohio ; G. W. R. S., of Va. : M. T., of N. Y. ; J. M., of N. J.; S. G., of N. Y.; J. A. B., of Fla.; A. E. T., of Ohio ; M. M. S., of Ill.; H. H. L., of R. I. ; J. H., of N. Y.; H. S., Jr., of N. Y.; W. B., of N. J.; S. B.,of Ohio; F. C. K.,ofN. Y.;T. S.,of Pa.; R. T., ofN. J.; H. D. W., of Mich.; S P., of Mas. ; E. B. W., ofN. C. ; Z. C., of Ill.; G. W. C.. of Wis.