113 
Royal Microscopical Society. 
of chloride of ammonium for chloride of sodium. A light semi- 
gelatinous substance was at once perceived to be formed in the 
liquid. This was boiled for several minutes, but was not dissolved. 
On cooling, it was found to consist of a brownish matrix, richly 
moleculate, and having imbedded numerous long, flat, quadrangular- 
plates like those of uric acid in sugary solutions. See Fig. 18. 
19. To solution of alkaline urate of soda at 100° Fahr., a hot 
concentrated solution of chloride of ammonium was added. A 
white gelatinous precipitate fell at once. It was amorphous and 
molecular both when formed and after cooling. 
20. To solution of alkaline urate at 100 3 , a hot concentrated 
solution of chloride of sodium was added. No precipitate occurred 
at the time ; but next day a gelatinous mass was found filling two- 
thirds of the liquid. It contained (a) small retractile spheres, 
almost homogeneous, with a tiny central cavity ; these were about 
as large as lymph-corpuscles, and were very like the spheres of 
carbonate of lime in gelatin ; they did not affect polarized light ; 
(b) large brown spheres variously aggregated ; granular, not 
fibrous ; not retractile ; denser at the surface than at the centre ; 
covered with radiating needles, just like cilia round an infusorium ; 
these with the rest of the forms were imbedded in a gelatinous 
stuff which was apparently condensed among the cilia, so that the 
cilia corresponded to an outer sphere of partly condensed matter 
aggregated round the dark spheres ; (c) rhombohedra, clear, thick, 
colourless, separate ; with forms intermediate between them and the 
spheres (a). See Fig. 20. 
21. To a solution of alkaline urate at 100°, a hot concentrated 
solution of chloride of potassium was added. A precipitate fell at 
once. It was, under the microscope, a mixture of semi-transparent, 
waxy-looking stuff, with bright granules and dark solid spheres in 
large coalesced masses. The spheres had central points (cavities) 
and indications of radial striation, but there were no needles. See 
Fig. 21. 
22. A hot but not very strong solution of phosphate of soda 
and a hot alkaline solution of urate of soda being mixed, no pre- 
cipitate occurred till the mixture was cooled. The whole mixture 
then became a firm jelly, which did not liquefy or subside after a 
portion had been scooped out, but remained with sharp edges after 
twenty-four hours. Under the microscope it consisted of soft com- 
pressible spheres and a structureless transparent gelatinous matrix. 
23. A very strong solution of phosphate of soda was mixed 
with equal bulk of solution of urate of soda at 100°. A precipitate 
speedily appeared. At the end of four hours this was found to 
contain large, beautiful, homogeneous, yellow spheres, presenting a 
black cross on pale white ground in the polariscope. The next 
day only half the spheres remained as at first, the other half being 
