_The thickness of colour'd Plates and Particles of_ _____________|_______________ / \ Air. Water. Glass. |---------+----------+----------+ {Very black | 1/2 | 3/8 | 10/31 | {Black | 1 | 3/4 | 20/31 | {Beginning of | | | | { Black | 2 | 1-1/2 | 1-2/7 | Their Colours of the {Blue | 2-2/5 | 1-4/5 | 1-11/22 | first Order, {White | 5-1/4 | 3-7/8 | 3-2/5 | {Yellow | 7-1/9 | 5-1/3 | 4-3/5 | {Orange | 8 | 6 | 5-1/6 | {Red | 9 | 6-3/4 | 5-4/5 | |---------+----------+----------| {Violet | 11-1/6 | 8-3/8 | 7-1/5 | {Indigo | 12-5/6 | 9-5/8 | 8-2/11 | {Blue | 14 | 10-1/2 | 9 | {Green | 15-1/8 | 11-2/3 | 9-5/7 | Of the second order, {Yellow | 16-2/7 | 12-1/5 | 10-2/5 | {Orange | 17-2/9 | 13 | 11-1/9 | {Bright red | 18-1/3 | 13-3/4 | 11-5/6 | {Scarlet | 19-2/3 | 14-3/4 | 12-2/3 | |---------+----------+----------| {Purple | 21 | 15-3/4 | 13-11/20 | {Indigo | 22-1/10 | 16-4/7 | 14-1/4 | {Blue | 23-2/5 | 17-11/20 | 15-1/10 | Of the third Order, {Green | 25-1/5 | 18-9/10 | 16-1/4 | {Yellow | 27-1/7 | 20-1/3 | 17-1/2 | {Red | 29 | 21-3/4 | 18-5/7 | {Bluish red | 32 | 24 | 20-2/3 | |---------+----------+----------| {Bluish green | 34 | 25-1/2 | 22 | {Green | 35-2/7 | 26-1/2 | 22-3/4 | Of the fourth Order, {Yellowish green | 36 | 27 | 23-2/9 | {Red | 40-1/3 | 30-1/4 | 26 | |---------+----------+----------| {Greenish blue | 46 | 34-1/2 | 29-2/3 | Of the fifth Order, {Red | 52-1/2 | 39-3/8 | 34 | |---------+----------+----------|