I further say, that it is my opinion, and clearly so, that the manufacture and sale of Nitro-Glycerin made according to the process described in your patent, does not infringe upon any of the five re-issued patents granted to the assignees of Nobel; and that so far as any of those re-issued patents are concerned, or anything else that I know of, you have a clear right to manufacture and sell Nitro-Glycerin according to your patent. Very respectfully, GEO. GIFFORD, Counsellor at Law. This discovery was not allowed to pass unchallenged, for Mr. Tal. P. Shaffner, having learnt that I had obtained a patent, came forward with a claim that he had conceived the idea (!) in 1865; and in January, 1869, nearly a year after the application for the patent which was granted to me, he applied for a patent for the same thing. This brought our respective rights before the Patent Office in a matter of interference. However, the following remarks by Mr. John W. Thacher, Examiner of Interferences, in giving his decision on the case, will show pretty clearly to whom the right to a patent justly belongs. He says: “The principle is well established that he who first reduces an invention to practical form is entitled to a patent therefor. Applying this test in this case, the right to a patent seems to rest entirely in Mowbray, and the invention is accordingly awarded to the patentee.” And again Mr. Samuel S. Fisher, the Commissioner of Patents, in giving his decision, remarks: “The story of Shaffner is not that of a man who had invented anything. He had a theory, talked about it, doubted its value; did not experiment to satisfy himself; until Mowbray was manufacturing on a large scale; and evidently did not intend to apply for a patent at all. I can find none of the ear-marks of a perfected invention, carried beyond the region of experiment; still less of any trace of diligence. Priority is awarded to Mowbray.” As previously noted, the Nobel patent with its re-issues, in four divisions, and twenty-four columns of specifications, containing eight claims drawn up expressly to intercept infringers, specifically, emphatically, and unmistakably insisted: 1st. That Nobel discovered it was necessary to confine Nitro-Glycerin in order to explode it, and that it was practically impossible to explode it unconfined. 2d. That heat and pressure were the agents necessary for a successful explosion of Nitro-Glycerin. The writer, however, discovered that the heat, pressure and confinement, claimed by the Nobel patent and re-issues, were unnecessary, by charging an open glass tube with Nitro-Glycerin, the glass tube being immersed in water, and the Nitro-Glycerin exploded by the concussion of a cap containing fulminate of mercury, and so succeeded in extricating himself from the domain of the Nobel patents and their particular claims.