Carbonate of Lime present in Calcareous Substances. 263 
The first thing to be furnished with, is an instrument, which 
consists simply of a tube about half an inch in diameter, and ° 
ten inches long, having the principal part of it graduated in one 
hundred parts. The simplest form to be given to this tube, is 
such as is represented in figure 1, the extremity a being drawn ~ 
out and bent downwards, leaving an opening so small as to allow 
a liquid to flow but slowly from the tube. ‘'T'o the upper part, for 
convenience’ sake, is adapted a perforated cork, with a small tube; 
this is placed for the purpose of regulating the flow of the fluid, 
by placing upon it and withdrawing from it the finger, as we 
may wish to arrest or allow the liquid to flow from the extremi- 
ty a. With this instrument, that I propose calling the Calcari- 
meter from its use, we must be furnished with two fluids, a solu- 
tion of muriatic or nitric acid, and a solution of ammonia, both of 
which are prepared of a certain strength.* 
Preparation of the acid solution.—This solution is prepared as 
follows: weigh out fifty grains of dry finely powdered pure carbo- 
nate of lime, or what is better, carbonate of lime precipitated from 
any of its solutions by carbonate of potash or soda; place this in 
a tea-cup or other convenient vessel, add to it about an ounce of 
water, (this is done simply for the purpose of moderating the ac- 
tion of the acid, ) then take the muriatic or nitric acid of commerce, 
dilute it with one part of water; with this liquid fill the instru- 
ment to the 100 point, then let the acid fall gently upon the 
carbonate of lime, so as not to create a too great effervescence, and 
by proceeding carefully with the aid of a piece of litmus paper, 
we can find the exact point at which the carbonate of lime is all 
taken up, by the solution having an acid reaction. When we see 
that nearly all the lime is taken up we proceed very cautiously, 
by adding but a few drops of the acid at a time, and agitating 
the mixture considerably, for the purpose of bringing the insolu- 
ble carbonate well in contact with the different parts of the 
fluid. When the acid reaction commences, the acid is no 
longer added, and the point at which the acid now stands in 
the tube is marked, and by subtracting that from 100 we have 
* The capacity of the instrument, from 0 to 100 is one ounce, and the length of 
the graduation had better be from eight to ten inches; of course this will vary with 
the diameter of the tube. As they are all to be of the same capacity, the graduation 
may be made upon the tube itself or upon a piece of paper and pasted on, then var- 
nished, first with a solution of gum arabic, and afterwards with copal varnish. 
