August 19, 1946

Mrs. Hazel Lindberg

7205 Southeast 35th Avenue

Portland, Oregon

Dear Hazel:

I am writing to report on the investigation of the solution which you gave me - although, I am sorry to say, I have no significant results to report.

The solution, so far as I can tell, does not contain any constituents not ordinarily present in perspiration. It contains about 0.05 percent of sodium chloride. It also contains some calcium ion, as well as organic constituents. The power of the solution to kill soap suds is small - I have been disappointed that it has not been possible to use this power as a means of isolating some substance. The concentrated solution in the form in which you gave it to me is not quite so effective as Pasadena tap water in killing soap suds. This power would be accounted for by the presence of about forty parts of calcium ion per million.

In the absence of an assay method (such as might have been provided by an extraordinary power to kill soap suds), there is no effective way of trying to isolate any particular unknown constituent.

There are two obvious possibilities. One of them is that the constituent which kills soap suds has been lost during the process of isolation and concentration which you carried out. The other is that the effect is due to the normal constituents of perspiration, and that it was made noticeable by an unusual tendency to perspire shown by the cancer patients. This tendency would, of course be very noticeable in Portland, with its unusually pure water, whereas it would be overlooked in other communities.

I have about half of the solution left. If you want me to return to you, I shall do so — I doubt that there is anything more that I can do. If you do not want me to return it, I might keep it, and subject it to any further test that I might think of later.

I am sorry that I have nothing more encouraging to report; however, the cancer problem is a very great one, and we can hardly hope to find an easy solution of it.

It was fine to see you in February.

With best regards, I am

Sincerely yours,

Linus Pauling

LP:gw