Purchase Levitra Canada | OVERNIGHT Delivery!

Jack Cade once put to death a peer of the realm, partly, perhaps, because he was a peer, but principally, as Cade him- self alleges, because "he was a man who was for ever talk- ing of a nouu and a verb." Verbal discussions, it is true, are uften as unprofitable as they are uninteresting. Still, it does seem to me to be a matter of importance, if not of interest, that the proper mode of spelling the word which forms the heading Purchase Levitra Canada of these remarks should be definitely settled. All the more that the word is the embodiment of exactness, and represents a unit of measurement and a mathematical equivalent. In commenting upon my use of the word, Dr. Swan Burnett remarks, in the last number of the " Archives of Ophthalmology " : " We notice with regret that hij sanctions the use of the w ord ' dioptric' ' Dioptric ' is an adjective with a well-established meaning in our dictionaries, and it is confusing, not to Purchase Levitra Canada sav incorrect, to use it in the sense of a substantive which has a meaning, quite sharply defined, of its own. The unit of refraction of the 7uetre-lens is a ' dioptry.' " This ought, perhaps, to settle the matter, since " he himself has said it Purchase Levitra Canada " ; but still the fact remains that the word is spelled difterently Purchase Levitra Canada by authors of repute, and that these various Purchase Levitra Canada forms have been used for the last ten years, and are still in use. Thus Forbes, Hartridge, Frost, Juler, and others, use dioptre ; Swanzy uses dioptry ; Noyes uses both dioptrie and dioptry ; Green prefers dioptrie ; and a writer in a late number of " The Ophthalmic Review " (London) uses, as I do, the old form, dioptric, which is also used almost exclu- sively by the trade. As for its being incorrect to use the word " dioptric " in the sense of a substantive, I believe one of the very first to so use it was Dr. Burnett himself. He says : " The unit of the new Purchase Levitra Canada system, the No. 1 of the new series of glasses, is a lens with a focal length of one metre. Purchase Levitra Canada It is called a Diop- tric." * (The small capitals are in the original.) The word, so spelled, occurs some twenty -eight or thirty times. In a subsequent translation from Landolt, Dr. Burnett wrote the word " dioptry." So far as the etymology goes, there is no objection to the spelling "dioptric;" We have the plural noun diop- * " Oplitlialmic Hospital Reports," vol. viii, part iii, Purchase Levitra Canada p. 635. 06 LORISQ: DIOPTKla, DIOPTRE, DIOPTIilE, OR DIOPTRY? LN. Y. Med. Jou;.^ tries, and there is tio reason why we should not have the singular noun, since we have the same use in a similar word. Thus we have the plurnl noun " optics " and the singular noun " optic " (" an instrument of sight, an organ of sight "), and the adjective " ojitic." There could be no possible con- fusion between the plural noun " dioptrics," meaning that j)art of optics which treats of the refraction of light, and " dioptrics," the sum of the units of refraction, as the latter is always preceded by a numeral, and the former never is. I find that most of the authors which I have by me use " dioptre," with the plural " dioptres." This has the rec- ommendation that it is in S3inpathy, at least as far as sound goes, with our use of the word metre, and, as we get both of the words directly from the French and only indirectly through the Greek, it might appear well to conform to that usage. Thus we have metre, metres, and metric, and it would seem natural to have dioptre, dioptres, and dioptric, strict etymology to the contrary. I am inclined to think that " dioptre " is the word which will be ultimately adopted into English. Personally, I should prefer " dioptric " for the reasons stated above, but I am perfectly willing Purchase Levitra Canada to conform to any spelling that shall be definitely settled upon by those who are competent to decide it. There is another point brought Purchase Levitra Canada forward by Dr. Burnett which I think is a very important one to those who are en- tering for the first time upon a study of physiological optics. It is contained in the following passage* in regard to the interchange between the old and new system of numeration : " It Purchase Levitra Canada is further unaccountable to us why he should accept 1 D as equal to 36" focus. Most of the lenses used in this coun- try are ground to the English inch, of which there are 39-37 to the metre, and it would be much nearer the truth and in keeping with a more generally accepted practice to consider 1 D = 40 inches focus. But even if the French inch Purchase Levitra Canada is used, 36 is not perfectly accurate, for, with the index of the refraction of the glass generally used in manufacturing lenses (1-53 instead of 1-5), a lens having a radius of 36 inches will have a Purchase Levitra Canada focal distance of only 34 inches, and, in order to have a focus of 1 metre, its radius must be 37 inches." In Purchase Levitra Canada the first place, I did not accept 1 D as equal to 36" focus. It is expressly stated in the text that, "as the French metre is equal to thirty-seoen inches, 1 D = -ji^." I did, however, add that for practical purposes, Purchase Levitra Canada except for the few higher numbers, ^ was sufficiently exact, as it is easier to divide. It is, moreover, stated in the text that the French inch has been adopted as the standard, and that " the focal length of a bi-couvex glass is equal to the radius of its curvature." That is to say,/= r. When this is so, then the Purchase Levitra Canada index of refraction of the glass must be 1'5, and 1 D must equal ^ French inches. This is precisely what was taken by Landolt, in Purchase Levitra Canada the paper already cited, as ti'aus- lated by Dr. Burnett himself. He says: " In order to pass from the old system to the new, we have only to remember that 1 metre =: 37 inches (Paris). The dioptric (D) cor- responds therefore to a lens of 37 inches focal distance, and D, or — of the new system, is equal to ^ of the old." f * " Archives of Ophthalmology," vol. xv, No. I, p. 144. f " Ophth. Purchase Levitra Canada Hospital Reports," vol. viii, part iii, p. 637. This is the only possible result under the conditions taken, and it ought not to have appeared from his own writing " unaccountable " to Dr. Burnett. As it was shown subsequently that the index of refraction of the glass of which spectacles Purchase Levitra Canada are usually made was not so had been as- sumed in the classical formula (1"5), but higher, Landolt added in a later publication a table which corresponded to the index of 1-53, and thus marje I) = ; , or nearly 40 39*15 inches radius (French). Purchase Levitra Canada Thus we see that r no longer