50 
THE NATURAL SCIENCE JOURNAL. 
was allowed to stand until it reached the 
required shade when the texture to be 
dyed was dipped. In the time of Augus¬ 
tus, wool thus colored was worth $200 
per pound. 
As Rome grew in wealth this dye grew 
in popularity, and it was fast becoming 
the only dress of the rich, when the edicts 
of the Emperors abolished its use by 
private citizens. This was a death blow 
to the industry—the Byzantine emperors 
going so far as to prohibit the use of 
purple ink. Gradually then the art be¬ 
gan to be practiced less and less, until 
it finally became lost. In the middle 
ages—justly termed dark—the very ex¬ 
istence of such a dye was considered 
fabulous. But with the discovery of 
America and closer trade relations with 
the east, came reports of brilliant fabrics 
colored from the juices of sea-snails. 
The accounts of Pliny and Aristotle 
were brought to light by learned men, 
and impulse was given to scientific inves¬ 
tigation. Numerous species yielding the 
purple dye were found, and for some 
time there was chance of its regaining its 
lost prestige, but the bringing of new 
dye-stuffs from America, the discovery 
of the value of cochineal in 1650, and 
the scientific advance in chemistry soon 
supplied it with dangerous rivals and 
made it but one among many beautiful 
dyes. Still, however, it is the color of 
royalty, and probably will always con¬ 
tinue so to be. 
A bronze figure just discovered in the 
Amsterdam Museum is believed by the 
director to be by Michael Angelo. It 
represents King David dancing naked 
before the ark. 
department of /IDieroseopp. 
Prof. ARTHUR M. EDWARDS, M. D., Editor. 
11 Washington St., Newakk, New Jersey. 
GLYOEEINE-GELATIN 
Prof. Arthur M. Edwards, M. D. 
OME objects may be mounted toler¬ 
ably permanently in other sub¬ 
stances than varnishes, as Canada balsam, 
gumthus and the like, and show their 
peculiarities very nicely. Glycerine- 
gelatin is a substance easy to manipu¬ 
late — easier than ordinary Canada bal¬ 
sam, although I believe that gumthus 
can be as easily manipulated. At any rate 
glycerine-gelatin is an easy substance to 
use, and where glycerine can be used 
with advantage and like some substances 
it is readily employed. Carbonate and 
phosphate of lime cannot be used with 
glycerine for they are both soluble in 
that substance. But when combined 
with gelatin it does not seem to dissolve 
them. However, these substances bet¬ 
ter not be mounted at all. But vegetable 
organisms can be so mounted and show 
very well. 
There is a preparation of glycerine- 
gelatin which I have at times employed, 
in which the gelatin and glycerine are 
preserved and made to keep without 
moulding, which has never been published. 
Glycerine of course is the substance 
which is used, and this is used because it 
does not mould or develop bacteria. It is 
harmful to use it however, for it takes 
the moisture from the air and so becomes 
dilute, and bacteria can then develop in 
it. This can be obviated by rendering it 
non-drying by the addition of gelatin, 
which itself does not take water from 
the air. 
