"This was my grandmother's (Dollie Cowan) recipe. She often served this at luncheons. Tomato aspic sounds a little strange to people nowadays, but it was very popular in the South in the 1930s-50s. Dollie served it on butter lettuce with a little mayonnaise on top."
Pour the tomatoes with the juice from the can into a saucepan over medium heat and heat until warm, about 5 minutes.
Dissolve the raspberry gelatin in the boiling water. Stir the unflavored gelatin into the cold water until dissolved. Add both mixtures to the warmed tomatoes and stir. Pour the tomato mixture into a gelatin mold and refrigerate until congealed, 3 to 4 hours.