THE NATURAL SCIENCE JOURNAL. 
51 
It also secures the presence of water 
into it which ordinarily does not dry up. 
But it has a property which is detrimental 
to the common use of it as a preserva¬ 
tive, and that is it renders substances too 
transparent for ordinary use, a substance 
which in the air is rendered obvious 
by the difference of what is known as the 
refractive index of that substance. That 
is to say a transparent substance like 
glass is rendered visible when viewed in 
air by the difference of the refractive in¬ 
dex of glass and air. It is not so trans¬ 
parent. When immersed is more trans¬ 
parent, and so on. So that substances 
can be viewed in different media accord¬ 
ing to the refractive index. 
Some substances like Bacillaria shells 
or diatoms formed of colored silica or 
onyx cannot be mounted in glycerine- 
gelatin at all. For they look so trans¬ 
parent that their shells cannot be seen. 
When living Bacillaria are mounted in 
that substance the endochrome and oil 
globules as they are called—they are 
female organs however—show pretty 
well, also exhibit their structure nicely. 
Calcareous shells, as the Foramenifera 
shoAV very nicely. 
Some years ago I experimented with 
this substance, glycerine-gelatin, and 
proved that this preparation works very 
well. Gelatin, I use Cooper’s fine gela¬ 
tin, is broken up and covered with cold 
water. It is left to stand over night. 
Next morning the water is poured off and 
the whole warmed in a water bottle. 
This is an outer vessel in which water is 
heated or made to boil, and the inner 
vessel which contains the gelatin is thus 
heated without exposing it to the open 
fire or sounds of heat. The gelatin is 
thus melted and to it is poured a suf¬ 
ficient quantity of strong glycerine. The 
quantity used varies according to the 
specimens used to mount. One part of 
glycerine to four of gelatin or one part 
to five, or even one part of glycerine to* 
six or eight of gelatin. To render it so 
that bacteria can not by any possibility 
form in it, I use a small quantity, a 
pinch will do, of pure salycilic acid, such 
as can be made from Oil of Satlieria 'pro- 
cumbens. I do not use ordinary salycilic 
acid, because although it is said to be 
salycilic acid, I think it is not so, at least 
it does not act the same on the animal sys¬ 
tem. With this glycerine-gelatin rendered 
safe with salycilic acid, I have found that 
it acts nicely, and have merely to recom¬ 
mend it for trial. 
It is reported that a new semi-precious 
stone has been discovered in Mexico. 
The lucky finder was an opal hunter who 
accidently came across the peculiar stone. 
The remarkaljle formation attracted his 
attention and he forwarded a sample to 
Mr. Edward J. Smith, a diamond expert 
of Chicago. Mr. Smith gave the sam¬ 
ples of the stone a careful examination 
and declares that they are unknown to 
the trade. He christened them “ Cly- 
clops.” These stones vary in size from 
that of a pea to that of a pecan nut. 
The stones are susceptible of a high pol¬ 
ish and in the center is a remarkable re¬ 
semblance to an eye. Mr. Smith stated 
that this new gem is fitted to be set in 
any kind of jewelry. Great secrecy is 
being maintained as to the locality in 
Mexico where the gem is to be found, 
until Mr. Smith and associates are suc¬ 
cessful in getting control of the deposit 
or mine.— SjjanisJi-American Inclnstrial 
Journo,1. 
