To the Editor.—
In the July 1985 Archives, Lamm et al1 properly and accurately call our attention to a histologic artifact associated with jet administration by Madajet.However, the Madajet is certainly not a "new needleless injection instrument," for we have used these types of instruments for many, many years (approximately 15). One must learn the proper distance from the skin from which to deliver any jet-propelled fluid, with or without particulate matter.2 In some anatomic areas, the plastic spacer provided with the instrument is adequate. In other loci, experience should quickly teach us that we must move an increased distance away from the skin to prevent largescale perforations of the epidermis and dermis. The delivery of anesthetic or dilute steroid suspensions through air space must be properly distanced, these distances varying between several millimeters to as much as 5 cm greater than the spacer would indicate. Given