1819.] Oxides and Salts of Mercury. 329 



This ointment has been used by many of the most eminent 

 surgeons in Dublin, both in private and hospital practice. It is 

 at present under trial in some of the public institutions ; but the 

 results, though favourable, I am not at yet at liberty to publish. 

 In the Lock Hospital it has been extensively used, and is still 

 under use. Such of the surgeons of that institution as have 

 already tried it extensively enough to form a decided opinion, 

 have favoured me with communications on the subject: these I 

 think it necessary to make known. 



Mr. Johnston's Letter. 



« MY DEAR SIR, Temple, Aug. 8, 1817- 



" I have complied with your desire of administering your new 

 mercurial ointment for the purpose of ascertaining its advantages 

 as a remedy in venereal affections ; and it is with much satisfac- 

 tion I have to state that the result of several trials has fully 

 confirmed your expectations. 



" Eight patients were selected from those under my care in the 

 Westmoreland Lock Hospital, who had not used any mercury, 

 and were put on a course of rubbings of this ointment. Every 

 one of them was able to rub in a drachm of it, perfectly dry, in 

 the short space of 15 minutes, and the succeeding rubbing 

 seldom required more than 12 or 13 minutes. Even those in a 

 weak state of health, from previous indisposition, experienced 

 equal facility with the most robust, in effecting this operation. 

 It produced the characteristic effects of mercury on the system 

 in general in a shorter period than I have observed to arise from 

 the employment of an equal quantity of the common blue oint- 

 ment.* In no case did the frictions with your ointment produce 

 any cutaneous eruption of the parts to interrupt the continuance 

 of its use, an effect which so often arises from the use of the old 

 ointment, and which obliges the practitioner to change this mode 

 of exhibiting mercury, perhaps greatly to the injury of his 

 patient. 



" These are advantages which, in my opinion, give the new 

 ointment a decided preference amongst the profession as an anti- 

 venereal remedy, and render it a valuable addition to the articles 

 of the materia medica. I regret that circumstances have obliged 

 me to be so brief, but for particulars I refer you to the inclosed 

 cases. " With every sentiment of regard, 



" I am, my dear Sir, yours, most sincerely, 



if To M. Donovan, &c." " Andrew Johnston." 



• This fact I also observed j and it has been remarked to me by surgeons, that 

 the new ointment arrests the progress of the disease morespeedil v than the common, 

 *wing no doubt to the facility aud completeness of its absorption. — M. U. 



