3i8 AN ADDRESS ON A NEW ANTISEPTIC DRESSING 



But, though its adhesion was satisfactory enough, it turned out that the 

 precipitate thus formed aggregated into a tenacious mass, which could not be 

 diffused uniformly through the gauze, and here I was again at fault. This 

 difficulty was overcome by first charging the gauze with the double-cyanide 

 powder diffused in water, and then transferring it to a starchy bath. This at 

 once fixed the cyanide in the gauze ; and, whereas, before it was placed in the 

 starchy bath, the slightest squeeze made a milky fluid exude, no sooner had it 

 been well penetrated by the starchy liquid than you might squeeze it as you 

 pleased, and nothing came out but a clear fluid. I was much pleased with 

 this, and it is in this way that I have prepared the gauze that I have used for 

 the last twelve months, both in the hospital and in private practice. Still, 

 this method had its disadvantages. When the gauze had been passed through 

 the fluid in which the double cyanide had been diffused without any starch, 

 it required very tender handling. If you gave it a squeeze, out came a quantity 

 of double cyanide ; and it was plain that, although one might do it oneself 

 satisfactorily, if we trusted to the manufacturers there would be an utter un- 

 certainty as to what quantity of material might ultimately remain in the gauze. 



Only lately has this difficulty been surmounted. It occurred to me that 

 perhaps if the starch were first blended with the double cyanide and then dried 

 and reduced to powder, if water were afterwards added to this dried dissolved 

 starch associated with the cyanide, there might not be the same tendency to 

 lumpiness and difficulty of diffusion. I found that the process did not answer 

 quite as I hoped in the first instance, in this respect ; that the dried starch 

 and double cyanide were extremely difficult to scrape off from any plate on which 

 they were put to dry, and also very difficult to pound up and to diffuse for 

 charging the gauze. But I got rid of these inconveniences by means of sulphate 

 of potash, used for the same reason as in the preparation of Dover's powder — 

 viz. that it is an inert substance, but with sharp, gritty particles. Mixing 

 a pretty strong solution of starch with the double-cyanide powder, and adding 

 to this a quantity of pounded sulphate of potash, the result is that you get 

 a material which, after drying, is easily scraped off by the manufacturer, and 

 easily reduced by him to an impalpable powder, which is then readily diffused 

 in water, and makes a perfectly uniform gauze ; being mixed in large quantity 

 with water in order to charge the gauze, the sulphate of potash is practically 

 got rid of, and if any of it remains it does no harm, because it is inert. Thus 

 we have the means of easily charging fabrics with this double cyanide. 



I have spoken of diffusing this preparation in water, but in reality we 

 employ for this purpose the i to 4,000 solution of bichloride of mercury, which 

 fortunately does not in any way interfere with the process. I may remark 



