BOARD QUESTIONS ANSWERED

AN IOWA EXAMINATION.

CHEMISTRY.

(Continued from the August BULLETIN OF PHARMACY.)

added iodine will be liberated and impart to the solution a light reddish-brown color. On agitating this mixture with a few drops of chloroform the latter will acquire a violet color.

Insoluble iodides should be transposed by hydrogen sulphide, the insoluble sulphide removed by filtration, the excess of hydrogen

Bromine, chlorine, fluorine and iodine, when exercising negative polarity, are called halo

gens.

Bromine, symbol Br, is a heavy, dark, brownish-red, mobile liquid evolving, even at ordinary temperatures, reddish fumes, highly irritating to the eyes and lungs, and having a peculiar suffocating odor, resembling that of chlorine. Its specific gravity is about 3.016 at 25° C. Bromine is soluble in 28 parts of water at 25° C., and readily soluble in alcohol or ether (with gradual decomposition of these liquids); also in carbon disulphide, and in chloroform, with a deep reddish color.

Its

Chlorine, symbol Cl, is a yellowish-green gaseous fluid, with a penetrating, suffocating odor. It is a supporter of combustion. specific gravity is 2.47. When the attempt is made to breathe it, even much diluted, it excites coughing and a sense of suffocation, and causes a discharge from the mucous membrane of the nostrils and bronchial tubes. Chlorine

manifests great affinity for hydrogen and hydrogen derivatives, most of the latter being so decomposed by the chlorine that hydrogen is removed from them, and hydrochloric acid is formed.

Fluorine, symbol F, in the free state is a greenish-yellow gas. Very little is known, however, concerning the properties of free fluorine because the intensity of its chemical energy is so great that it cannot be retained in an uncombined state long enough to study it. Its atomic weight is 18.9.

taste.

Iodine, symbol I, consists of heavy, bluishblack, dry and friable plates, having a metallic lustre, a distinctive odor, and a sharp and acrid Its specific gravity is 4.948. It is soluble in about 5000 parts of water, and in 10 parts of alcohol at 25° C.; freely soluble in ether, chloroform, or carbon disulphide. Iodine volatilizes slowly at ordinary temperatures.

6. Give indentification tests for iodides. If to 5 Cc. of an aqueous solution (1 in 20) of a soluble iodide 1 Cc. of chlorine water be

then tested for hydriodic acid by means of chlorine water and chloroform.

7. Name the natural source of the following elements: (a) As, (b) I, (c) Hg, (d) P. (c) K.

(a) Arsenic occurs in the free state, but more abundantly in the form of sulphides and other compounds. The most common arsenical ores are realgar, As S2; orpiment, As-S; arsenical pyrites, FeAsS; and "kupfernickel," NiAs.

(b) Iodine accompanies chlorine and bromine, the halides of these three elements being generally found together in sea-salts and in The ashes of salt-springs and salt deposits. sea-plants contain iodides. Large quantities

of iodine are also obtained from the residues of the mother liquids collected in the process of separating sodium nitrate from the saltpeter deposits of Chili.

(c) Mercury occurs in nature in the form of crystallized mercuric sulphide called cinnabar.

(d) Phosphorus occurs mainly in the form of calcium phosphate in the mineral apatite and in bones.

(c) Potassium occurs abundantly in the granite rocks in the form of silicate in combination with other silicates. Hence it also occurs in soils derived from these rocks, and in plants growing in such soils. Another source is acid tartrate of potassium, called "tartar” and "argols," which is deposited from the fermented juice of grapes in the making of wine. The most abundant source of all, however, is the potassium salts found associated with magnesium salts in the immense salt beds at Stassfurth, Germany.

8. Complete the following equations: (a) 2KCIO+4HCl=? (b)K+H2O—?

(a) When potassium chlorate and hydrochloric acid are brought together the following reaction takes place:

KCIO+6HCI-KC1+3H2O+6Cl.

Therefore if 2 parts of KCIO, were mixed with 4 parts of HCl there would be formed

The incompatibility in this prescription is quite pronounced. When chalk mixture has aromatic sulphuric acid added to it, carbon dioxide is liberated and calcium sulphate formed. Bismuth subnitrate also liberates carbon dioxide from chalk mixtures, probably causing the formation of some bismuth subcarbonate and a calcium compound. If the prescription is filled as written a combination which is probably quite different from the one intended by the physician results. For that reason the doctor should be asked to modify it. 10. Criticize the following:

Tincture of ferric chloride...2 fluidrachms.
Spirit of nitrous ether..... .4 fluidrachms.
Powdered acacia
Syrup

.3 drachms. .i fluidounce.

Peppermint water, to make...3 fluidounces. Make a mixture.

Directions: Teaspoonful three times daily.

In compounding this prescription the acacia should first be mixed with the peppermint water in order to form a mucilage. Mucilage of acacia, however, is incompatible with both of the first two ingredients, forming a gelatinous semi-solid with chloride of iron, and being precipitated in a ropy rubber-like condition by the alcohol in both.

To make a presentable mixture, first fortify the mucilage with the syrup, then add the other ingredients a few drops at a time, shaking thoroughly after each addition, and give time for the mucilage

Unless care in manipulation is exercised the guaiac resin from the tincture will be thrown out of solution. To make a presentable mixture, place the honey in a mortar and triturate with it the tincture of guaiac, added in small portions. Then dissolve the potassium chlorate in the water and mix with the honey and guaiac. Finally, add the tincture of cinchona compound to which the oil of peppermint has previously been added.

12. Criticize the following:

Oil of turpentine....
Powdered tragacanth
Syrup of orange.
Water, to make..

Mix and make an emulsion.

.8 Cc.

.1 gramme. 15 Cc. ..60 Cc.

LETTERS

COMMERCIAL EPSOM SALT IN EGYPT.

To the Editors:

Here is the account of an experience which may prove of interest to BULLETIN readers who make it a practice to test their purchased chemicals:

Not long ago I was in the market for a barrel of Epsom salt, but before buying a lot of good appearance that was shown me I decided to make a few purity tests. Accordingly I dissolved a small quantity; no change was evident at first, but after standing for fifteen or twenty minutes a cloudy, yellowish-red appearance developed which some hours later resolved itself into a yellowish-red precipitate.

I was inclined to believe that the precipitate might be caused by the water of our country, which comes from artesian wells, and which contains salts of calcium likely to combine with part of the sulphate in the Epsom salt to form calcium sulphate. Therefore, I made up a solution of the salt with distilled water, which solution did not develop a cloudiness or precipitate.

Upon testing for iron, however, I found the cause of my difficulty. The iron in the Epsom salt combined with the carbonates present in the artesian well water to form ferrous carbonate, which upon standing was changed to ferric oxide (in a solution saturated with carbon dioxide). Hence the yellowish-red cloudiness and precipitate.

The sample tested also gave a reaction for chlorides with silver nitrate. Arsenic I did not. find.

Because of these discoveries I decided to test other samples in order to see if all commercial Epsom salts contained the same impurities. I procured from my store a packet of the salt in stock there and subjected it to examination. No iron was found.

I determined to assay it for identity, however, because from the formation of the crystals I doubted its genuineness. Tests applied convinced me that the article supplied to me under an Epsom salt label was not magnesium sulphate but sodium sulphate!

When I called up the dealer who had "sold" me, he insisted that the substance sent me was really Epsom salt. Then I asked him to make

an assay himself in order to convince me that I was wrong. Two days later he telephoned that I was very right and that he intended to return the ten barrels of spurious product that he had on hand.

He further informed me that he had a lot of genuine Epsom in stock, and I ordered a sample of it. This time it was really magnesium sulphate, but contaminated with iron as was the first package. Thereupon I purchased a quantity from another dealer, after convincing myself as to its genuineness and purity.

Hereafter when I buy magnesium sulphate or sodium sulphate I am going to test it. JOHN N. KOUTOUPAS.

Zeitoun (near Cairo), Egypt.

EDUCATING THE PUBLIC.

To the Editors:

For the purpose of acquainting the public with the constant price changes-mostly upward-which have been brought about by the European war, the editor of the Houston Chronicle publishes occasional letters over my signature.

Here is my letter which appeared in July under the caption "The High Cost of Drugs": High prices continue in drugs, dyestuffs, leather, paper, and glassware.

Since the writer published an elaborate price list of chemicals in January last, it is not necessary to do so again, as the public is fully aware of the fact that most of the drugs have since that time increased very rapidly. Some items-very popular indeed-have gone up in value steadily.

Castor oil, cod-liver oil, and senna leaves are the latest on the list of advanced values. The ever-popular moth balls come very high this season, as they have to be sold from 25 to 35 cents per pound. Even Paris green, London purple, and chloride of lime, three very necessary and seasonable drugs, are advancing in price so steadily that at present we cannot tell what or when the end of the upward movement will be.

As a consolation, however, we must report that a few drugs in the past two months-have actually declined. You can soon kill your malaria with cheap quinine again and use carbolic acid and mercury as freely as ever. Glycerin also has been good enough to come down somewhat from the high-price pedestal.

The dyer and laundryman are still kicking about the enormous value of oxalic acid and about the utter absence of green and blue aniline dyes, and others about the high price of citric acid.

The people at large have lots of complaints to lodge against the effects of the war.

The bottles of ink and the size of the writing tablets have a changed look for smallness; glassware and tinware cost a great deal more than they did three