378 Rectification of Alcohol. 
several of their most worthy members, among whom was 
professor Pictet, of Geneva, who had presided at the session 
of 1820, has attended all the meetings since the commence- 
ment of the Institution, and contributed richly to its useful 
labours. The meetings were attended by 76 members, ex- 
clusive of those of the Canton, in which they were assembled. 
Among the memoirs read on the first day of the session, 
was one by Professor De Candolle, of Geneva, on the pro- 
perties of a reddish matter, from the surface of the lake of 
Morat, where it appeared during the spring; after a season 
of calms, disposed in zones, along the borders of the lake, 
and especially among the reeds. In this substance were 
found two distinct matters. Ist. A greenish and fetid sedi- 
ment, which left the supernatant water of a fine red colour. 
2d. A lamellar substance, in irregular shreds, of a soft and 
spongy consistence. ‘The first of these matters, submitted to 
a powerful microscope, presented to De Candolle, Dr. Pre- 
vost, and Vaucher, all the characters of an oscillatoria, the 
motions of the zoophytes being distinctly perceptible. It 
was named by De Candolle, oscillatoria purpurea. A chemi- 
cal examination of this substance proved that it consisted of, 
Ist. A red colouring matter, partly soluble in alcohol. 2d. 
Of chlorophylla. 3d. Of gelatine in large proportion. 4th. 
Of albumen. 5th. Of some earthy and alkaline salts, and a 
little oxide of iron, These results confirm the opinion of 
some naturalists, with respect to the animal nature of pro- 
ductions which are met with in a great number of mineral 
waters, and lend support to the observations of Vauquelin, 
on the green substance of the waters of Vichy, in which he 
met with a substance which had a close analogy to albumen. 
3. Rectification of Alcohol without heat.—As a means of 
obtaining strong and pure alcohol, without the aid of heat, 
or of an alembic, it is recommended by M. E. Pajot-Des- — 
charme, to place the spirituous material, whether low wine or 
Holland proof, in a deep vase with a flat bottom, and within 
this vase, supported by feet resting on its bottom, place a 
broad dish, containing dry muriate of lime ; cover the whole 
very closely, by pasting paper around the edges of the vase. 
In four or five days the salt will have deliquesced by the 
attraction of moisture. Replace the apparatus, after replen- 
ishing the dish with dry muriate. By continuing the opera- 
