Comprising a set of 8 substances (approximately 2g each) with melting points as follows:
Stearic acid: 69.7ºC
Benzil: 94.8ºC
Acetanilide: 113.9ºC
Benzoin: 134.8ºC
Adipic acid: 150.6ºC
Benzanilide: 161.6ºC
2-Cyanoguanidine: 209.4ºC
Saccharin: 226.5ºC