MISCELLANEA. 
421 
to dissolve. Before employing the chloride of zinc, it is heated uith a small quantity 
of oxide of zinc, in order to neutralize any excess of acid in the chloride, and then fil¬ 
tered through a piece of fine cambric to remove the superabundant oxide. To separate 
the chloride of zinc from the solution of silk, M. Persoz has recourse to Professor Graham’s 
method of dialysis. The apparatus for dialysis, which is a kind of sieve, is made by 
means of a broad strip of gutta-percha, bent round and cemented in the form of a 
cylinder, at one end of which is fixed a disc of parchment to form the bottom. The 
apparatus is floated upon a vessel of water, and the silk solution, previously diluted with 
water to the consistency of collodion, is poured into it. The chloride of zinc percolates 
through the moistened disc of parchment, and mixes with the water in which the appa¬ 
ratus is floating. In a few days the whole of the chloride of zinc will be found to have 
become separated from the silk solution, but the presence of a slight quantity of the 
chloride in the material is of no great consequence, as it merely gives rise to the forma¬ 
tion, in the sensitive film, of a minute quantity of chloride of silver. Although M. 
Persoz does not mention the fact, there is no doubt that a dry film of this substance 
would be quite insoluble in water. Its employment is very simple. It is first iodized 
by mixing with it an aqueous solution of iodide, and then dried and sensitized; the ex¬ 
posure and development are conducted in the ordinary manner .—Journal of the 
Society of Arts. 
Identification of Strychnine.—Mr. T. P. Blunt, in the ‘ Chemical News ’ of 
November 30, writes as follows:—“The following means of identifying strychnine may 
prove useful, under certain circumstances, as a corroboration of other tests; I do not 
think it has been previously noticed. In the examination of animal mixtures for 
strychnine, it is very difficult to separate that base from traces of organic matter; these 
may nearly always be recognised in the residue of evaf)oration from ether or alcohol by 
their smell, and appear—especially where the latter solvent is used—to interfere with 
the characteristic crystallization of that base in tufts of needles, which we find replaced, 
either wholly or partially, by granules, which to the naked eye appear to be devoid of 
crystalline character, but, under the microscope, are seen to consist of short and gene¬ 
rally very irregular prisms. If a drop of dilute sulphuric acid (one of strong acid to five 
of water) be now added, the fragments will in a few seconds be observed to swell, as¬ 
suming at the same time a rounded appearance, and if examined after an hour will be 
seen to form the centres of tufts of acicular crystals, sometimes of great beauty and re¬ 
gularity, sometimes appearing more like a mass of radiating hairs, retaining the shape 
of the original crystal, but much increased in size. The fragment is wasted in the pro¬ 
cess, its residue often appearing as a nucleus for the stellar tuft. The drop of liquid at 
the same time becomes filled with well-defined stars, formed of radiating needles of 
smaller size and scattered amongst the greater tufts. If an acid stronger than that 
described above be used, solution ensues immediately without any of these pheno¬ 
mena. In crystallizing pure strychnine from alcohol, especially where the original 
solution is weak, portions of the base will often take the irregular prismatic form above 
mentioned, appearing thus upon the sides of the vessel exposed during evaporation.” 
Cochineal.—The imports of cochineal from the 1st of January to the 1st of Sep¬ 
tember last amounted to 4662 bags of Honduras, 870 bags of Mexican, and 6460 bags 
of Teneriffe, making a total of 11,992 bags; the deliveries to 3928 bags of Honduras, 
809 bags of Mexican, and 7852 bags of Teneriffe, making a total of 12,589 bags; and 
the stock in hand to 2687 bags of Honduras, 666 bags of Mexican, and 1709 bags of 
Teneriffe, making a total of 5062 bags. The imports to the same period. last year 
amounted to a total of 8535 bags, the deliveries to 10,664 bags, and the stock on hand 
to 4939 bags. 
Thoroughly Disinfected. —According to the‘New York Journal of Medicine, 
Dr. Charles Brockhausen, assistant physician at the City Hospital, St. Louis, having 
finished his rounds through the hospital wards one day recently, was about to proceed 
to the cholera tents, but before doing so concluded to take a glass of what he termed 
metaphorically “ disinfectant,” but what in the vulgar is known as brandy. There hap¬ 
pened to be on his shelf two demijohns, very similar in appearance, one of whicfficon- 
tained brandy, while in the other was a disinfectant known as chloride of zinc. The 
doctor hastily mixed him a potation and swallowed it at a draught. His sensations 
after taking it were peculiar. He perceived at once that he had taken his disinfectant 
