1)R. CHISHOLM ON THE MAL1S DRACUNCULUS. 561 
represented to have been in on shipboard. On the other hand, 
there is much reason for believing, as I have already said, that 
the ova of the dracunculi were received into the system by the 
stomach, and deposited in the cellular membrane, and, having 
attained their period of evolution, appeared in the persons of the 
soldiers in such numbers as to induce my respected friend to 
assign the disease to contagion, in the figurative sense in which 
the word is usually received. The period of evolution corre- 
sponds, it will be observed, precisely with the narrative Sir James 
Macgrigor has given, and with the history so clearly stated by 
M. Dubois. The very interesting account of the acarus siro of 
Madeira, there called ougoes by Dr. Adams, is a fine exempli- 
fication of the contagion of insects, or of the exanthemata viva. 
(See Medical and Surgical Journal of Edinburgh, vol. iii, p. 343.) 
It now remains to offer my observations on the prevention and 
cure of the dracunculus. Never was there a disease to which 
the medical precept, sublata causa, tollitur morbus , more dis- 
tinctly applies than this. The result of the application of this 
precept at Point Saline, in Grenada, is a manifest exemplifica- 
tion of the means by which this is to be effected, and precludes 
the necessity for saying more on the subject here. As to the 
cure of the disease, that is to be accomplished by the destruction 
of the insect. I used a variety of means, but none effectual, 
until I had recourse to mercury. Mildly saturating the system 
with this medicine destroyed the insect. I since then find that 
this medicine has been long used by others for this purpose. 
At that time, 1794, I knew no authority for it. Linnseus says, 
'* Infuso mercurii sublimati corrosivi Swietenii, intra dies 20, 
qui alias intra 40 educitur” ( Si/st . Nat., tom. i, p. 2, 1075). 
In phtiriasis, and other diseases of the exanthemata viva, mer- 
cury has been long known as an effectual remedy, externally 
applied ; but in dracunculus it is not so ; the remedy must per- 
vade the system, in order to destroy the insect or its ova. It is 
unnecessary to detail the variety of means employed in different 
countries. They are of doubtful effect, however vaunted of — 
asafcetida, garlic, the root of angelica, sulphur, &c. &c. Some 
gentlemen, considering the disease as an inanimate substance, 
recommend the extraction of it by a painful surgical operation; 
but the opinion is as irrational as the cure is unnecessarily 
cruel. 
