384. Mr. Brougham’s Experiments and Observations 
cannot doubt that in crystallization the smallest masses assume 
the same form with the largest : but then other hypotheses 
may perhaps also account for the fact, such as atmospheres, 
electric fluid, &c. &c.; so that till farther observations are made 
we ought to rest contented with barely suggesting the query. 
In the mean time, reserving to a future opportunity some in- 
quiries concerning the chemical properties of light, and the 
nature of the forces which bodies exert on it internally, I con- 
clude at present with a short summary of propositions. But 
first, may I be permitted to express a ’hope, that what has been 
already attempted (and for which no praise can be claimed far- 
ther than what is due to attentive observation, according to the 
rules of the immortal Bacon), may prove acceptable to such 
as love to admire the beautiful regularity of nature, or more 
particularly to trace her operations, as exhibited in one of the 
most pleasing, most important, and most unerring walks of 
physical science. 
Proposition I. The sun’s light consists of parts which differ in 
degree of refrangity, reflexity, inflexity, and deflexity; and the 
rays which are most flexible have also the greatest refrangity, re- 
flexity, andflexity; or are most refrangile, rejiexile , and flexile. 
Proposition II. Rays of compound light passing through 
the spheres of flexion and falling on the bending body, are not 
separated by their flexibility, either in their approach to, or 
return from the body. 
Proposition III. The colours of thin and those of thick plates 
are precisely of the same nature ; differing only in the thick- 
ness of the plate which forms them. 
Proposition IV. The colours of plates are caused by flexion, 
and may be produced without any transmission whatever. 
