ACCOUNT OF THE PROCEEDINGS OF THE ROYAL SOCIETY 



FROM NOVEMBER 1801, TO JULY 1802. 



From the Journals of the Royal Institution. 



1 HE meetings of the Royal Society commenced for the 

 season, on Thursday the 5th of November. 



The Croonian lecture on muscular motion, by Everard 

 Home, Esq. was read. Its subject wasthe capacity of theeye 

 to change its focal distance, after being deprived of the crys- 

 talline lens. Mr. Home relates an experiment, where it was 

 shown, by Dr. Young's optometer, that a person, from whose 

 eyes the lens had been extracted, retained a greater power of 

 accommo<lating it to different distances, than is found in 

 some eyes which are entire. On repeating the experiment, the 

 faculty appeared to be considerably diminished; a circum- 

 stance which Mr Home attributes to fatigue. The opto- 

 meter was found to be much more manageable in its simple 

 state, than with the addition of a lens ; and it was singular, 

 that this person saw distinctly from about 9 to 13 inches 

 without the use of any glass. 



On the 12th and 17th, Dr. Young's Bakerian lecmre was 

 read. The subject was the theory of light and colours. It 

 contained an extension of the system, which the author 

 had submitted to the Royal Society in a former paper ; and 

 its unexpected application to a great variety of phenome- 

 na, most of which had been observed by Newton, but 

 never sufficiently explained, and others were advanced from 

 the author's own experiments. Dr. Young first shows 

 bow little difficulty there is, for such as admit the New- 

 tonian doctrines, to allow the truth of this theory, and how 

 much those doctrines have been misunderstood by Euler 

 and others. After recapitulating and extending the expla- 

 nation of the more common phenomena of optics, the au- 



thor enters into the detail of those applications which are the 

 most novel and striking ; by which it appears to be a gene- 

 ral law, that, whenever two portions of the same pencil of 

 light arrive at the same point by different routes, the pro- 

 duction of colours depends uniformly on the difference of 

 the length of those routes ; and from this principle, the co- 

 lours of striated surfaces, of thin and of thick plates, and of 

 inflected light, are shown to be necessary consequences of 

 the combination of undulations, in the same manner as 

 the beating of two sounds, or the interference of the tides 

 at sea : and all the measures, laid down by Newton, are 

 found to agree precisely with this law. Such a coinci- 

 dence Dr. Young cannot help considering as fully sufficient, 

 to turn the scale of probability in favour of the undulatory 

 system of light. 



On the aflth, Mr. Hatchett's paper, on a new metallic 

 substance, found in an ore from the state of Massachusets, 

 was read. It appears to resemble in its properties the me- 

 tallic acids, and, in its namral state, is combined with"iron; 

 but is distinguishable from other substances, by the orange 

 coloured precipitate thrown down from its solution by the 

 gallic acid, and the olive green colour of the precipitate by 

 the prussic acid. All attempts to reduce it to the metallic 

 form have hitherto been unsuccessful: but, from the colours 

 of the precipitates, and from other circumstatices, Mr. Hat- 

 chett thinks that its base will be found to be an acidifiable 

 metal, and he gives it the name columbium. 

 On the 30th, the day of the anniversary, the Copleian me- 

 dal was conferred by the council on Mr. Astley Cooper, in 



