Here's a well-dressed young lady on ice skates, showing off her box of Soapine, which appears to feature a whale on the front.
Indeed, it is a whale. The Boston Athenaeum Digital Collections feature another Soapine advertising card. And, in that one, the Kendall Mfg. Co. product works so well that a beached whale has been scrubbed snow white.
It's kind of sad and creepy, what happened to the whale. Buy, hey, it was a great soap!
P.S. — A 32-page booklet titled Soapine Did It! An Illustrated History of Kendall's 19th Century Soap Advertising Campaign, written by Dave Cheadle and W.H. "Bill" Lee, was published in 2000. No used copies are currently available through Amazon, but there may be other ways to acquire a copy, if you're interested.