ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
135 
Alcohol and hydrochloric acid. — 50 per cent, alcohol, 100 ccm. ; 
Hydrochloric acid, concentrated, 5 ccm. 
Iodized alcohol.— 35 per cent, or 70 per cent, alcohol, 100 ccm.; 
Tincture of iodine, 2 * 5 ccm. 
Chrom-acetic acid, No. 1. — 1 per cent, chromic acid, 100 ccm. ; 
Concentrated acetic acid, 5 ccm. 
Chrom-acetic acid, No. 2. — Concentrated acetic acid, 100 ccm. ; 1 per 
cent, chromic acid, 10 ccm. 
Chrom-osmic acid. — 1 per cent, chromic acid, 100 ccm. ; 1 per cent, 
osmic acid, 2 ccm. 
Chrom-picric acid. — 1 per cent, chromic acid, Kleinenberg’s picro- 
sulphuric acid, equal parts. 
Copper sulphate and corrosive sublimate. — 10 per cent, solution of 
copper sulphate, 100 ccm. ; saturated solution of corrosive sublimate, 
10 ccm. 
Potassium bichromate and osmic acid. — 5 per cent, solution of 
potassium bichromate, 100 ccm. ; 1 per cent, osmic acid, 2 ccm. 
Corrosive sublimate and acetic acid. — Saturated solution of corrosive 
sublimate, 100 ccm. ; concentrated acetic acid, 50 ccm. 
Corrosive sublimate and^ chromic acid. — Saturated solution of 
chromic sublimate, 100 ccm. ; 1 per cent, chromic acid, 50 ccm. 
Frequently great difficulty is experienced in killing an animal 
without producing a considerable amount of contraction, and in the 
case of elongated forms, such as Nemerteans and other worms, without 
causing them to coil up or become twisted, To avoid this, it is ex- 
pedient to narcotize the animals before killing them, and for this 
purpose Lo Bianco recommends immersion in weak alcohol. He uses 
generally a mixture of sea-water 100 ccm. and absolute alcohol 5 ccm. 
In other cases 70 per cent, alcohol may be carefully poured upon water 
in which the specimen lies, so that it forms a layer at the surface. It 
will gradually mix with the subjacent water, and in the course of a few 
hours will narcotize the animal, so that it may be treated with fixing 
reagents without fear of contraction. 
Chloral hydrate, 1 to two parts sea-water, is also efficient as a nar- 
cotizing agent, and has the advantage of allowing a recovery of the animal, 
if there should be necessity for it, by placing it in fresh sea-water. For 
some sea-anemones tobacco smoke is useful, the smoke being conducted by 
a Y-shaped tube into a bell-jar covering the vessel of sea- water in which 
is the anemone. Certain of these reagents will prove most satisfactory 
with some animals, others with others. Lo Bianco details the best 
method for treating the various forms in a second portion of his paper, 
and an account of some of his methods of procedure, so far as they concern 
forms which resemble those found upon our coast, may now be presented. 
Sponges. — Direct immersion in 70 per cent, alcohol, with subsequent 
renewal of the fluid, is recommended for the majority of forms. To 
avoid contraction in the case of the Halisarcidae, they should be left for 
half an hour in 1 per cent chromic acid, or in concentrated solution of 
corrosive sublimate for fifteen minutes. To prepare dried specimens the 
sponges should be washed in fresh water for a few hours, and then 
allowed to remain in ordinary alcohol for a day, after which they may be 
dried in the sun. 
