602 
CONVERSAZIONE. 
fluid drachms being rejected, and then the product collected until one fluid ounce 
was left in the retort. 
The distillate in this case was free from any smell of sulphurous acid. Its 
specific gravity was 1843. One fluid drachm (100-8 grains) of this acid was 
neutralized by 202 measures of the volumetric solution of soda, indicating that 
it contained more than one atom of water to the atom of anhydrous acid. 
CONVERSAZIONE. 
The usual annual Conversazione was held in the Society’s rooms on Tuesday 
evening, the 17th of May, and a large number of visitors, together with Mem¬ 
bers and Associates of the Society, responded to the invitations which had been 
issued by the President and Council. 
The following objects, for which the Council were indebted to the gentlemen 
■who kindly contributed them for the evening, were distributed through the 
rooms:—Portrait of Jacob Bell, by Sir Edwin Landseer, R.A., from Mr. T. 
H. Hills; portraits of celebrated scientific men, by J. Gilbert and Walker, 
and specimen of microscopical writing, from Mr. W. L. Bird ; landscapes by 
Richardson, Copley and Thales Fielding, and the sketch by W. Frith, R.A., 
from which the “ Coming of Age” was painted, from Messrs. Vokins; a hand¬ 
some and interesting emblematical shield of Shakspeare, from John Leighton, 
F.S.A.; a rare and valuable German black-letter copy of u Terence,” of the 
fifteenth century, a rubbing from Shakspeare’s tomb, and a collection of auto¬ 
graphs, from Mr. H. Campkin, ; a memorial of Shakspeare, carved from Herne’s 
oak and an apple-tree in Anne Hathaway’s garden, from Messrs. Rogers ; 
specimens of Japanese ivory ware and Russian goldsmith’s work, from Messrs. 
Phillips ; several busts, from T. Butler, Esq., sculptor of the marble bust of 
Jacob Bell; some statuettes and busts, from Mr. Claudet, illustrating an in¬ 
genious application of photography which has been recently made in Paris, and 
to which the name of Photosculpture has been applied by M. Willeme, its 
inventor. By this process, busts and statues of living persons are prepared in 
plaster and u biscuit,” which possess much of that faithfulness and minute ac¬ 
curacy of detail which are so striking in photographic portraits. The principle of 
the new art is easily explained. The person whose bust or statue is to be taken 
is placed in the centre of a circular apartment forty feet in diameter, and 
twenty-four camerse obscurm are placed along the wall at equal distances from 
him and from each other. By means of a latch, which raises and drops the slides 
at the same moment, twenty-four photographs are taken at the same instant of 
the sitter. He is thus represented from twenty-four points of view. There are 
of course six front views, six back views, and twelve side views, so that a clever 
artist would find in these photographs all the materials for a piece of sculpture 
to be fashioned by the eye. But this is not the course taken, mechanical pro¬ 
cesses being adopted which ensure much greater accuracy. The negative of one 
of the portraits is placed in a mhgic lantern, and the image printed upon it is 
projected on a large sheet of rough glass. The block of clay in which the 
model is to be cut is then placed on a revolving stand, the circumference of 
which is divided into twenty-four parts. A pantograph is next employed, by 
which the clay is cut exactly to represent the outline on the glass. When one 
photograph has been copied, the image of the next is placed in the lantern, and 
the clay is turned round one twenty-fourth part of a Circle. It is then copied, 
and so on with the twenty-four negatives. The result is that the block of clay 
exhibits twenty-four sides, or facets, representing exactly the outlines of the 
twenty-four photographs. Of course there are ridges left which must be 
smoothed down, and this process is entrusted to skilful artists. Several flint 
implements from Abbeville and St. Acheul, Amiens, from John Evans, Esq. ; a 
