Improvements in catheters / [Alfred Walsh].

  • Walsh, Alfred.
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: Improvements in catheters / [Alfred Walsh]. Source: Wellcome Collection.

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    9 N° 13,453.—A.D. 1895. Walshy MaWy V'/iompsony and Maw's Improvements in Catheters. the interior of the catheter so that the foundation tube of woven fabric is entirely enveloped and enclosed within the gum elastic. We make the improved catheters in the following way : — 1 he woven silk tube which serves as the foundation is stretched upon an iron wire, the wire being inserted into it, then as usual the woven tube is coated with semi-fluid gum 5 elastic. The so called gum elastic is a composition consisting of copal varnish, burnt or highly boiled linseed oil and a small quantity of linseed oil in its natural or unboiled state. When the coating of gum elastic has hardened the wire is withdrawn from the woven tube. Next another coating of gum elastic is applied 10 to the exterior of the woven tube and after this in turn has hardened it is followed by other coatings and so on, coating after coating being applied say daily, until the exterior covering of gum elastic has attained to nearly its full thickness. Each successive coating is hardened by exposure in an oven heated by steam to a temperature of 170 to 180 Fahrenheit or thereabout. 15 All these operations are such as are usual in the manufacture of catheters. At this stage the coating for the interior of the catheter is commenced by pouring the gum elastic through it and allowing it to drain out. An exterior coating of gum elastic may be applied at the same operation. In this way the catheter receives about six internal coatings, each coating being hardened before the next 20 is applied. Finally the smoothing and polishing of the surfaces has to be performed ; for the exterior this is done in the usual way on a travelling band with polishing powder consisting of rouge and pumice. The interior is smoothed and polished with the same polishing powder mixed with a little oil, it is applied by means of a wire and the wire is worked about within the catheter by hand 25 continually until no roughness or unevenness is discernable. In catheters thus made every part of the surface both within and without is of the non-absorbent gum elastic and the woven foundation tube is completely and inaccessibly buried in the gum elastic. The smooth impervious surface of the gum elastic affords no shelter for bacteria and it can be cleaned with facility. 30 Having now particularly described and ascertained the nature of our said inven¬ tion and in what manner the same is to be performed we declare that what we claim is :— A gum elastic catheter made substantially as described and having its interior as veil as its exterior surface of smooth or polished gum elastic. 35 Dated this 4th day of March 1896. ALFRED WALSH. CHARLES MAW. J. THOMPSON. C. TRENTIIAM MAW. 40 London: Printed for Her MajeHty’a Stationery Office,by Darling & Son, Ltd.—18°6