syrup), cakes, pies, ice cream, etc., in other words, articles of food which would be classified as sweets. In this particular camp it was found that the average soldier bought in the neighborhood of 500 calories of energy every day in the form of sweets. This represents fairly typical conditions. Wherever it has been possible to estimate with any degree of accuracy at all the consumption of food from these exchanges, we have found figures ranging in the neighborhood of those just quoted. We may say, then, that the average soldier craves in the form of sweets, which represent quick energy in much the same way that alcohol in small quantity represents quick energy for the body, food amounting to about one eighth of his total daily requirements. The question may fairly be asked whether the government would not be well advised to reduce the quota of meat and replace the amount thus saved with sweets, provided as a part of the ration.

Still another question of great interest, not only for the army but for the entire civilian population, is the question of dehydrated vegetables. As a means of preservation and therefore of conservation of our food supply, dehydration or drying has already proved its place. By means of improved appliances, this measure may now be extended to classes of food stuffs not ordinarily preserved by drying. Potatoes, cabbage, spinach, strawberries and many other articles usually preserved by other means may now be dehydrated much more effectively than by ordinary means of drying, and may be preserved in this dehydrated condition for a considerable length of time, if not indefinitely. The importance of this measure for the army lies in the saving of tonnage or cargo space in transportation of food materials across the country and across the water. Major Samuel C. Prescott, of the Food Division, has pre

pared an exhaustive report on the subject of dehydration covering all phases of the subject from the saving in the space to the chemical composition and microbiology of the product. Immediately after this report was submitted to the Quartermaster Department, that department began placing orders for dehydrated vegetables such as potatoes, onions and carrots for the use of General Pershing's army. As yet the tonnage contracted for is not large, but in all probability in the very near future dehydrated vegetables will become a staple article in our army rations, as they have already become in the ration of the British army. Thousands of tons of dehydrated vegetables are being prepared in Canada, some also in the United States for the British army. By simply soaking in water and boiling in the same water, these vegetables are brought back to the condition of fresh vegetables so perfectly that very often they can not be distinguished from the fresh vegetables themselves. Another advantage of such products is the very high saving of time in the company kitchen. Dehydrated vegetables put up in packages are ready for the kettle; this saves the work of one or two men a day.

It is fairly safe to predict that before very long methods will be found for the dehydration of meat as have already been found for the dehydration of milk. Such measures remove many dangers of food poisoning. Meat spoilage is almost entirely due to imperfect refrigeration, but if the water is taken out of the meat, it does not need to be refrigerated. Bacteria can not grow without water. The Food Division through investigation made at the Harriman Research Laboratory in New York, has already found a satisfactory method of making meat powder, by dehydration at low temperature and a high vacuum. This can be used as a component of soup

stock or dried hash which requires only a short soaking in water and boiling to make a very delicious dish. The Bureau of Chemistry under the direction of Dr. Alsberg is also working on this problem, as is also the Bureau of Animal Industry under Dr. Mohler. There should be, as a result of these studies, in time a very large saving in the cost of living, Imagine the difference in the cost of transportation of milk with and without its water content, quite aside from the saving in the cost of refrigeration. Milk is 88 per cent. water, meat is about 70 per cent. water. Practically all of the water can be extracted from milk, leaving a powder which will go into solution readily and, by combining with sweet butter, can be turned out as a product of any desired composition. Already it is possible to deliver milk of this kind, which at current retail prices costs 14 cents a quart, for less than 9 cents a quart. There should be a corresponding saving in the cost of meat, for two of the largest factors in the cost of meat to-day are refrigeration and freight charges. In the case of milk, the reconstituted article is just as palatable as the original milk and is very much safer, for it can be pasteurized twice, once just before powdering, and again just after reconstitution with little extra cost. In the case of meat in the form of soup stock, hash and stew, which form the bulk of meat consumption in the army, the product again is just as palatable as the original meat.

There are many other aspects of the problem of nutrition of the army which would interest you had I the time to take them up in detail. One of the most interesting to us in the office has been the preparation of some special rations for the use of our own American prisoners in Germany and for the use of sick soldiers and prisoners. One of the first things the Food Division was asked

to do after its organization early in September was the preparation of an American Prisoners' ration. This request came from the American Red Cross, and after a few days we had prepared for them a ration which could be shipped in bulk to the Red Cross Headquarters at Berne, Switzerland, and packed in parcels not to exceed 11 pounds in weight, according to the specifications required by the German government, and sent three times every two weeks to the American prisoners held in Germany. It was our task to see that such a parcel contained enough food value for the American prisoner to last him until the next parcel should be due to arrive. Articles had to be selected which could be packed in small cartons, and which would be certain to keep for the necessary length of time. These articles also had to be such as could be prepared readily for eating under the limited facilities of the prison camp. The list as finally made up runs somewhat as follows: rice, sugar, dried beef, pork and beans, peanut butter, soda crackers, evaporated milk, milk chocolate, desiccated strawberry, jam, nutmargarine and dried figs. Provision was also made for variation and substitution such as tea for coffee, marmalade for jam, oleo for nutmargarine, dried apples, apricots, etc., for dried figs, hominy for rice, corned beef for dried beef, etc. I think we may all feel comforted by the thought that if an American soldier is taken prisoner, he will, by this beneficent arrangement of the Red Cross, at least be well fed. Information which seems to be perfectly reliable from the Red Cross representatives at Berne assures us that the British provisions for their soldiers, which are quite similar to ours, are not interfered with, in any way, by the German government at the present time.

The requirements of the sick soldier are very different from those of the healthy

soldier. Considerably more latitude is required in the selection of foods which may tempt the appetite of the soldier, if ill in bed. The realization of these facts led to another request from the Red Cross for a ration to be known as the Invalid Ration. This was designed in the first instance for American prisoners in Germany too ill to be out of bed, but it has been thought that the same ration could be used also by sick soldiers in our own hospitals in this country. This ration therefore has been constructed with the idea that it could be used by sick soldiers anywhere in our own service, or in the prison camp. The ration has been approved by the President and adopted. It follows: unpolished rice, yellow cornmeal, sugar, potted chicken, Julienne or compressed soup tablets, dried milk powder of malted milk, beef extract, minute tapioca or other form of prepared pudding crackers, tea, milk chocolate, marmalade, fresh fruit or fruit juice. These articles, however, are regarded as only supplementary to those of the regular ration, whether prisoners' ration or the garrison ration.

It is comforting just now to remember that the status of the science of nutrition in America is fully equal to its status in the land of our enemies at the beginning of the war. If we fail in the trial that is upon us, it will not be for lack of information. If we fail to keep our civilian population properly nourished, it will not be because we do not know the functions of food, or because we do not know what foods are suitable. Likewise with the army.

Our own government has been foremost in the support of scientific investigations along these lines. The names of Atwater, Chittenden, Lusk, Benedict, Mendel, Osborne, Taylor, McCollum, Alsberg, Armsby

are known wherever the science of nutrition is studied, and the completeness of their work is openly admired and envied in Eng

land, France, Scandinavia, and even in Germany. Immediately preceding the outbreak of the war, no less than a dozen young German investigators of promise had studied in American laboratories, because the work of several of these laboratories was considerably in advance of similar laboratories in Germany or Austria. The support of these laboratories by the national government, by state governments, and by our wealthy benefactors, Carnegie, Rockefeller, Mrs. Sage and others was responsible for their splendid equipment. But the leadership also was not lacking. In fact, the scientific leadership pointed the way to the benefactions and governmental appropriations. JOHN R. MURLIN

FOOD DIVISION,

SURGEON-GENERAL'S OFFICE,
WASHINGTON, D. C.

ICELAND SPAR IN MONTANA THE existence of large deposits of pure calcite has recently been brought to the attention of the Bureau of Mines. These deposits occur near Gray Cliff, Montana, and have been inspected by Dr. S. C. Lind, of the Bureau. At the present time there is no considerable market for pure calcite. It is used for the manufacture of some kinds of glass. Perfect crystals of calcite are used in certain optical instruments. In the past practically all the optical material has been mined from one deposit in Iceland. The crystals from the Montana deposit appear to be the nearest approach to Iceland spar yet uncovered in any part of the world.

Since the seventeenth century science requirements for optically perfect calcite have been supplied almost wholly from the wellknown but small deposit on the east coast of Iceland. This is a very remarkable occurrence, consisting of a cavity in basalt completely filled with enormous crystals of pure calcite.

Rhombohedrons and scalenohehedrons with diameters as great as three feet have not been uncommon. In recent years, however, the

difficulty in securing first class spar from the Iceland deposit has steadily increased, much of the material taken out being useless for optical purposes.

Occasional finds of doubly refracting spar have been made elsewhere without resulting in the development of a new supply.

While the total amount of spar required is not great, the maintenance of a certain production is necessary for the manufacture of Nicols prisms to be used in dichroscopes for testing pleochroism of gem stones, polariscopes, polarizing microscopes and saccharimeters. Other substances having as great a difference in the refractive indices of the ordinary and extraordinary rays are all unsuitable for replacing Iceland spar in optical instruments.

It is possible that the Montana veins might be made to return a commercial product of spar if they were worked with sufficient care. From one vein six hundred pounds of crystals are said to have been shipped to an agent who sold the spar in Germany, receiving $3,000 therefor. These crystals had been sorted from thirty to forty tons of calcite blasted out in the sinking of a seventy-fivefoot shaft.

The Montana deposit lies in two vertical veins in gneiss. The veins are four to seven feet wide, probably at least 100 feet deep, and are several miles long. The deposits are near the surface, easily mined, and quite accessible to the railroad. The crystals practically fill the entire vein without any admixture of foreign intrusions.

So far, no absolutely perfect crystals have been obtained from these veins, but it is altogether likely that a better product may be had by more careful mining. The imperfections are of two kinds. Some crystals have a very slight, gray cloudiness, which renders them unsuitable for optical purposes. This defect is inherent. The bulk of the material, however, while perfectly clear shows slight cleavage in the interior of the crystals. This may be and probably is due to the shocks to which the crystals are subjected in mining.

Some of the crystals were obtained by the Bureau of Mines and submitted to the Bureau

of Standards for test. Their report is quoted below.

The larger sample does show interference colors in places in its body as noted by We are not, however, of the opinion that this renders the whole crystal useless for optical purposes. It would appear that good material for small optical parts (e. g., small Nicols prisms) might be cut from this crystal.

It is also true that the smaller sample is very slightly turbid (milky). This makes it not strictly first class, but for some purposes would not impair its use. Otherwise it is an exquisite sample. We would like to have for our own use a considerable supply of material.

If a market could be developed for pure calcite to pay for mining a large tonnage of these deposits, it appears altogether probable that good optical crystals could be obtained as a by-product in quantity sufficient for all scientific requirements, and so meet the need caused by the diminishing output from Iceland.

BUREAU OF MINES, WASHINGTON

CHAS. L. PARSONS

SCIENTIFIC EVENTS

INVENTIONS SECTION OF THE GENERAL
STAFF OF THE DEPARTMENT OF WAR

THE following statement is authorized by the War Department:

In order to secure prompt and thorough investigation of inventions submitted to the War Department an "Inventions Section " has been created as an agency within the General Staff. All inventions of a mechanical, electrical, or chemical nature submitted to the War Department for inspection, test, or sale are now considered by this section.

Inventions may be sent by mail or may be submitted in person, accompanied by written descriptions or drawings. They go first to an examining board having technical knowledge of the classes of inventions they handle, whose investigations determine whether the inventions have merit. Those with merit are referred to the Advisory Board, which determines in each case whether it should be put in the hands of some of the numerous testing and

developing agencies, or if it should go to one of the staff or supply departments for test and consideration of its adoption, and final acquirement of title if such action is desirable.

Composing the Advisory Board at present are the following: D. W. Brunton, member Naval Consulting Board and chairman War Committee of Technical Societies; Dr. Graham Edgar, member National Research Council; Colonel James W. Furlow, Quartermaster Department, chief of Motors Division; Colonel J. A. Hornsby, M.C., chief of Hospital Division, Surgeon General's Office; Lieutenant Colonel Morgan L. Brett, Ordnance Department, Engineering Branch; Lieutenant Colonel Robert A. Millikan, S.C., chief of Science and Research Division; Lieutenant Colonel N. H. Slaughter, S.C., chief of Radio Development Section; Major Joseph A. Mauborgne, S.C., chief of Electrical Engineering Section.

When completed the board will have 12 to 15 members to cover fully all of the various technical problems which may come before it.

In testing and developing inventions and in considering problems presented by staff departments, the Advisory Board works in connection with a number of agencies. Among them are the following: National Research Council; Bureau of Standards; War Committee of National Technical Societies (this committee consists of two members detailed from each of the 10 important technical societies in the United States); laboratories and shops of the staff and supply departments of the Army; Patent Office; Aircraft Production Board; all Army service schools; C. L. Norton, Massachusetts Institute of Technology, Cambridge, Mass.; Dr. Charles P. Steinmetz, General Electric Co., Schenectady, N. Y.; A. H. Beyer, chairman committee on testing laboratory, Columbia University, Broadway and 117th Street, New York City; R. R. Abbott, metallurgist, Peerless Motor Car Co., Cleveland, Ohio; Dr. John A. Matthews, president Halcomb Steel Co., Syracuse, N. Y.; Knox Taylor, president Taylor-Wharton Iron & Steel Co., High Bridge, N. J.; Howard D. Colman, Baber-Colman Co., Rockford, Ill.; Preston S. Miller, Electrical Testing Labora

tories, Eightieth Street and East End Avenue, New York City; Herbert Fisher Moore, University of Illinois, Urbana, Ill.; L. F. Miller, metallurgist, Mitchell Moore Co., 1832 Asylum Avenue, Racine, Wis.; E. J. Okey, the Timken Roller Bearing Co., Canton, Ohio; Dr. Aleš Hrdlička, curator division of physical anthropology, United States National Museum, Washington, D. C.

Any person desiring to submit an invention for consideration, test, sale or development should do so by letter, giving in order the following information: Name and object of the invention; any claim for superiority or novelty; any results obtained by actual experiment; whether the invention is patented; whether remuneration is expected; whether the invention has been before any other agency; whether the writer is owner or agent; the number of inclosures with the letter. A written description and sketches or drawings of sufficient detail to afford a full understanding of the cases should also be submitted. Should the invention be an explosive or other chemical combination, the ingredients and processes of mixture should be stated.

The Inventions Section will not bear the expense of preparation of drawings and descriptions, nor advance funds for personal or travelling expenses of inventors.

Any matter submitted will be treated as confidential. The inventor will be notified of each step taken during the investigation of his invention. All communications should be addressed: Inventions Section, General Staff, Army War College, Washington, D. C.

THE VOLUNTEER MEDICAL RESERVE CORPS

DR. FRANKLIN MARTIN, member of the advisory commission and chairman of the general medical board of the Council of National Defense, authorizes the statement that following out the plans for organizing the volunteer medical service corps, to enlist the services of physicians ineligible for camp or field duty, the medical section of the Council of National Defense is sending to several thousand doctors a letter which says in part:

The Council of National Defense has authorized and directed the medical section of the council to