Composition for detecting moisture leakage

Claim 1

A COMPOSITION FOR APPLICATION AS A PERMANENT COATING TO THE EXTERIOR SURFACE OF A CONTAINER FOR WATER AT ELEVATED TEMPERATURES AND THROUGH WHICH SURFACE SAID WATER MAY LEAK, WHICH WHEN APPLIED AS A COATING AND DRIED WILL BE RESISTANT TO HIGH ATMOSPHERIC HUMIDITY AND TEMPERATURES TO WHICH IT MAY BE EXPOSED, AND WHICH WHEN SO APPLIED WILL CLEARLY INDICATE THE EXISTENCE AND LOCATION OF ANY SUCH LEAK THAT MAY SUBSEQUENTLY DEVELOP, WHICH COMPRISES A COATING MIXTURE CONTAINING A FIRST POWDERED MATERIAL OF LEAD CHLORIDE WHICH IS SUBSTANTIALLY INSOLUBLE AND CHEMICALLY STABLE IN WATER AT APPROXIMATELY USUAL ROOM TEMPERATURES AND BELOW, BUT SUBSTANTIALLY SOLUBLE AND CHEMICALLY STABLE IN WATER AT TEMPERATURES WELL ABOVE THE USUAL ROOM TEMPERATURES, A SECOND POWDERED MATERIAL SELECTED FROM THE GROUP CONSISTING OF MANGANESE DIOXIDE, FERRIC OXIDE, AND GRAPHITE HAVING A COLOR SUBSTANTIALLY CONTRASTING WITH THAT OF SAID FIRST POWDERED MATERIAL, INSOLUBLE IN WATER AT ALL TEMPERATURES, AND CHEMICALLY STABLE AT TEMPERATURES WITHIN THE RANGE TO WHICH SAID SURFACE MAY BE SUBJECTED, AND A GEL-LIKE BINDER CONTAINING A COMPOUND OF SILICON IN AN AQUEOUS CARRIER MEDIUM WHICH BINDER IS CHEMICALLY STABLE AND SUBSTANTIALLY UNAFFECTED BY HIGH ATMOSPHERIC HUMIDITY AND TEMPERATURES FROM BELOW ROOM TEMPERATURES TO TEMPERATURES ABOVE THOSE TO WHICH THE COATING MAY BE EXPOSED IN USE, WHEREBY WHEN A LEAK OF WATER AT ELEVATED TEMPERATURES OCCURS IN SAID SURFACE COVERED BY SAID COATING, SAID FIRST POWDERED MATERIAL AT THE LEAK WILL BE DISSOLVED BY THE ESCAPING WATER AND CARRIED TO THE SURFACE OF THE COATING WHERE THE ESCAPING WATER CARRIED WILL EVAPORATE AND LEAVE A DEPOSIT OF SAID FIRST POWDERED MATERIAL ON THE SURFACE OF THE COATING WHERE ITS COLOR CONTRASTING WITH THAT OF THE COATING WILL INDICATE THE EXISTENCE AND LOCATION OF A LEAK IN SAID CONTAINER.