the skill of so many eminent chemists and photologists ofevery nation. Suffice it to say, that, after the intro-duction of M. Claudet’s accelerating process by the appli-cation of chloride of iodine and chloride of bromine (aninvention which lie liberally gave to the public throughthe medium of the Royal Society and the Academic desSciences); the Daguerreotype process , as publicly prac-tised, became reduced to some system, and two Daguerreo-type establishments were formed in London . The portraitstaken, at this time, were, however, deficient in expression;but in spite of all deficiencies, the receipts of theseestablishments several times amounted to GO/, in one day.
At a somewhat later period that remarkable variety ofthe Talbotype process, designated by its inventor by thename of “ Kalotype ” was also publicly employed for theproduction of portraits by Mr. Collen : the artistic effectin these representations was susceptible of being muchheightened by the brush and the defects of expressionmight be removed, and the likeness in consequence greatlyimproved by one or more subsequent sittings.
M. Claudet, who, from the earliest time of the Daguer-rian invention, displayed great genius and ability in per-fecting the various processes, first perceived the necessityof aiding the artistic effect of his representations b}' subsi-diary adjuncts of a different kind. lie it was who first prac-tised the placing of painted back-grounds behind the personswhose portraits were to be taken. Thus an infinite varietyof scene might be afforded by the operator simply pro-viding himself with a few subjects skilfully adapted tothe requirements of the occasion. To him also we owethat extremely pleasing adaptation of mechanical adjust-ments for bringing many miniature representations of thesame individual under different aspects, to be impressedin regular compartments of the same plate and framedtogether,—of which we find specimens exhibited in hiscollection.
It is not necessary to detail, step by step, the successiveimprovements in the different processes and apparatus forDaguerreotypic Photography, though we may mentionthat to the exertions of Messrs. Claudet, Gaudin, Fizeau,and Draper, the public are indebted for many improve-ments. To M. Fizeau is due the reproduction of theproofs of electrotype; also a new process for engravingthe Daguerrian image, and of preserving that image fromdestruction by gilding the surface.
The Exhibition presents many fine ealotypes, or as theyare sometimes called in the Catalogue “sun-pictures,” forthe production of which the preparations of Mr. Talbothold the first rank. M. Bayard, also, has been celebratedfor his achievements in this line, and has contributedmany splendid proofs, obtained on various sensitive papers.Mr. Talbot has, himself, exhibited nothing; but many ofhis productions will be recognized among those exhibitedby IIenneman and Malone, as adapted to the practicalwants of travellers, collectors, &c. This branch of theart offers inestimable advantages, viz.: 1st, That thepapers may be prepared at leisure, some time before anoccasion for using them arrives; 2ndly, That when pressedand fixed, they may be carried without injury in a port-folio, like other drawings; 3rdly, That from one goodnegative original, any number of positive copies may betaken, to the extent, indeed, of two or three hundredcopies in a rainy day , as proved by the practice of M.Evkrard Blaxquart (France , No. 1551), and suppliedto the public at a cheap rate; 4thly, That they may bewholly obliterated so as to reduce them apparently to theoriginal condition of white paper, and carried about inthat state for an indefinite period, though susceptible ofrevival at any instant. Considering it probable that thefollowing communication, addressed by M. Arago to theAcademy of Sciences , on the granting a national recom-pense to M. Daguerre, may be as useful to a portion ofthe public, now r , as then; we subjoin it in the words ofM. Arago himself:—
“ A short time after the law was voted, granting anational recompense to M. Daguerre, some opinions,which in my idea were very erroneous, were entertainedby a small portion of the public, which rendered it neces-sary for me to show that the discoverv, newly made, wasnot to be estimated in respect to art only, but to the very
valuable subjects for investigation which it presented inreference to the physical sciences.”
■Without further remark, we proceed to the discussionof the Potographs exhibited.
Datjucrreotype Piet in es.
Claudet (No. 296, pp. 440, 441) has exhibited a largecollection of daguerreotype portraits, both plain andcoloured. Amongst various excellences of which theyare possessed, we may particularly mention that oftheir non-inverting . This is a great improvement, and byit M. Claudet has annulled the superiority which the sun-pictures have so long possessed, in this particular, overthe daguerreotypes.
On examining the uncoloured specimens exhibited byClaudet, it will be found that they are distinguished byartistic arrangement, judicious distribution of light and: shade, and great clearness of definition. The generalI tone is good,—M. Claudet having uniformly avoided, violent contrasts of light and shade; a circumstance to! which much of his success may be attributed. In thiscollection are several female portraits in white draperies,which pictures deserve commendation for their beauty ofdetail and freedom from solarization. Many of the aboveremarks apply, equally, to the coloured specimens, mostof which are portraits, and are distinguished by careful| and harmonious colouring, the focus having been so judi-1 ciously selected, and most of them present an artistic and\ natural appearance, seldom hitherto obtained by Daguer-reotypists.
Photography may be said to be too faithfully exact inits results, for the purposes of art; detailing, as it does,the accessories in the hack ground and the main object ofthe group with equal fidelity. When blending colour! with photographic works, or in visibly uniting art andscience on the same plate, the operator should be pos-sessed of knowledge and feeling sufficient to know theproportions in which art and science should intermingleso as to be subservient to each other: in this knowledge,which is chiefly dependent upon the proper focal adjust-ments of the picture, M. Claudet excels; and the admi-rable manner in which he sacrifices the details, affordedhim by science, to the requirements of his subject, is theresult of long and laborious investigation.
An uncoloured daguerreotype by Claudet is worthy ofparticular mention ; it represents various articles of vertff,pictures, &c., grouped together: the perfect focus of eachpart and general relief of the whole prove it to be a suc-cessful application of his focimeter.
M. Claudet also exhibits the dynactimometer* andj focimeter. lie also exhibits the effects of the spectrumon the daguerreotype plate, as prepared by him, and ai variety of curious and instructive specimens illustrativei of the different refrangible rays. The Council Medal! was awarded to M. Claudet.
Kilburn (No. 294, p. 440) has exhibited a case con-taining several carefully-selected specimens of coloureddaguerreotypes. The subjects of these pictures are con-fined to groups of figures of small size, and are verybrilliant and elaborate in their details,—too much so forartistic effect. For novelty of design we may mention asmall picture of the interior of a room, including a wholelength portrait of Jenny Lind : beside, and near her, is alarge mirror, in which the figure is reflected. That thereflection in the glass is equally perfect with the originalis the point worthy of remark and commendation. To-wards the centre of this case is a plain daguerreotypeportrait of the Queen. The finish and execution of thislittle work are very great. The Jury awarded a PrizeMedal to Mr. Kilburn.
Mayall (No. 291, pp. 439, 440) has exhibited in thisdepartment a large collection of daguerreotypes, un-coloured. They are characterized by great contrasts of
* The reader is referred for an account of the dynacti-mometer to the “ Reports of the British Association,”August 1850, and to the “ Philosophical Magazine,” June1851, and for the focimeter, to the British AssociationReports,” September 1S49, and “ Philosophical Magazine,”November 1S49.