to personal observation and inquiry extending from Connecticut to as far north as Hamilton Inlet in Labrador. The biology of the subject relates not so much to the habits of Salmo salar as it does to the behavior of Homo sapiens with his specific appellation selfchosen.

ROBERT T. MORRIS

616 MADISON AVENUE, NEW YORK

EFFICIENCY IN THERMAL PHENOMENA

TO THE EDITOR OF SCIENCE: Mr. Forbes's theory of something being wrong with the commonly accepted definitions of efficiency in thermal phenomena, is provocative of comment. The question of a definition being wrong depends, obviously, on how it is interpreted.

In general the efficiency of a machine or mechanical process, is defined as the ratio of output to input. It is assumed that the output will always be less than the input, hence the efficiency will be less than unity.

It is safe to say that the difficulties alluded to by Mr. Forbes can be traced to failure to distinguish between the quantities of energy called input and output, and the units in which they are measured. In the electric heater, the input, watts, is wholly converted into heat, with efficiency of 100 per cent. In the electric motor the input, watts, is converted into 95 per cent. work and five per cent. heat, giving 95 per cent. efficiency if work output is considered, and 100 per cent. efficiency for the entire output. In the steam engine the input, heat, is converted into ten per cent. work and 90 per cent. heat, giving an efficiency of ten per cent. based on work output, 90 per cent. efficiency based on the exhaust steam for heating, and 100 per cent. for the entire output. In the refrigerating machine the output is, logically, heat carried away by the condenser water. The input, on the same reasoning, is made up of two parts, the heat removed from the brine and the work of driving the machine. The sum of the two input quantities is equal to the output, giving 100 per cent. efficiency as in all the other cases.

The refrigerating engineer recognizes the

difficulty of applying the term efficiency to his machine, and substitutes for it the term "coefficient of performance," the ratio of heat absorbed to the work required to drive the machine, both expressed in the same units. If efficiency is defined by the input-output formula, it is true that the efficiency of all machines is 100 per cent. If only a portion of the input or output is considered, it is possible to have efficiencies of less or more than 100 per cent. In this case it would be appropriate to use the term "partial efficiency," since the entire output is not considered.

E. H. LOCKWOOD

THE HELIUM ARC AS A GENERATOR OF HIGH FREQUENCY OSCILLATIONS

HELIUM as a conducting medium in a lowvoltage arc may be of considerable utility as a convenient source for generating, from direct current, oscillations of moderately high frequency.

Due to its exceptionally low sparking potential arcs may be readily started from a hot tungsten cathode by 110 volts even when the gas is at atmospheric pressure. In fact it is easy to start the arc across a centimeter gap between cold electrodes by means of breaking a parallel circuit with a series reactance common to both. Perhaps a more convenient method of starting, however, is the heating of the filament by the source of supply and then a commutation of the connection to the positive terminal from the filament to the anode.

When the proper inductance and capacity are connected across the arc high frequency oscillations are produced which may be utilized in the usual way with a coupled cir cuit. Hitherto, hydrogen and compounds of hydrogen have been used in areas to produce high frequency and it is very difficult to produce oscillations by the use of other gases at atmospheric pressure. Helium, however, probably due to its high heat conductivity, being inferior only to hydrogen in this respect, from the rapid rate of energy dissipation in the arc, gives the type of volt ampere

SCIENTIFIC BOOKS

Collected Studies on the Pathology of War Gas Poisoning, from the Department of Bacteriology and Pathology, Medical Science Section, Chemical Warfare Service, under the direction of M. C. WINTERNITZ, major, M. C., U. S. A. Yale University Press, New Haven, Conn. Cloth, 165 pages, 41 color plates, 83 black and white illustrations, $20.00.

The study of the pathological lesions produced by the war gases upon animals under controlled experimental conditions was of eminent practical importance during the war, and quite justly enlisted the interest and services of many of the foremost pathologists, both here and abroad. Without such control, it would have been difficult and, in many cases, impossible, to draw conclusions as to the comparative effectiveness of different types of gas used in offense; and to estimate the protection afforded by various defensive measures. Equally important was the desirability of defining, so far as this was possible, the effects of the various gases used by the enemy against our troops, and to afford criteria to the pathologists in the field by which they might be recognized.

The studies of Winternitz and his coworkers, which were available to the Chemical Warfare Service during the war, have now been made generally accessible in a comprehensive and beautifully illustrated monograph from the Yale University Press. On the basis of a very large experimental material, the gross and microscopic changes following exposure to chlorine, phosgene, chlorpicrin, trichloro

methyl-chloroformate (diphosgene, superpalite), dichloroethylsulphide (mustard gas), cyanogen chloride and bromide, arsine, and several organic arsine-halogen compounds are minutely described. Unlike most of the reports which have previously appeared, the study includes a consideration of late residual lesions as well as the acuter changes, and this phase of the work will prove of particular interest to those who still are seeking an anatomical explanation for the chronic invalidism which afflicts so many of the soldiers gassed in the war. The writers find quite regularly in the lungs after recovery from phosgene, persistent emphysema and atelectasis, associated with obliterating bronchiolitis, and with tubercle-like peribronchial nodules. On the

other hand, it is stated that "chronic changes in the lungs after mustard gas inhalation were infrequent and were confined to minute areas of organization occurring in isolated bronchioles or in the alveolar tissue near the margin of the lungs. In no case was any large bronchus found organized or occluded." In a few dogs, localized ulceration or cicatricial stenosis was found in the trachea. This rarity of permanent lesions after gassing with mustard in dogs does not accord with our own experience in the human cases. Without entering into details, it may be confidently stated that the inhalation of mustard gas in man is frequently followed by chronic changes in the entire respiratory tract. These differ, of course, in their extent and severity, but in many cases there results a destruction and deformity comparable to that of chronic pulmonary tuberculosis. In this connection, it is perhaps proper to emphasize the limitations of these and similar experimental studies on the war gases, in their application to human pathology. Whereas the experimental worker with animals was informed as to the kind of gas used, its concentration and the duration of exposure, none of these data were available to the pathologist in the field. Frequently, it happened that the same soldier was exposed to several varieties of gas within a short period; frequently, also, there were complicating traumatic injuries. Most disturbing of all were the supervening

bacterial infections, and particularly the epidemic influenzal pneumonia which swept through our troops during the period when gas casualties were most numerous. Because of these complexities, many of the human cases presented a difficult problem for the pathologist, and it was not very easy for him to apply fully the knowledge gained from animal experimentation. For example, although blue cross shells containing diphenylchlorarsine were used in profusion against our troops in the later months of the war, and although animal experiments had shown this and related arsine compounds to possess a high degree of toxicity, not a single casualty amongst 576 recorded autopsies could be referred to organic arsine-halogen compounds alone, nor was it possible to differentiate the lesions from those of other vesicant and irritant gases in common

use.

Such considerations should not detract from the value of the work. These studies, and the equally painstaking and complete experimental work of Warthin and Weller on Mustard Gas, are fundamental contributions to the pathology of the toxic gases used in the war.

Appended to the purely descriptive studies of gas lesions of various types, is an interesting chapter given to the subject of intratracheal therapy. It was found that dogs will tolerate intrapulmonary irrigation with physiological salt solution in amounts up to three liters, or more, when the fluid is introduced over a period of thirty minutes. Resorption from the lungs takes place very rapidly as could be shown by the elimination of phenolsulphonthalein in the urine; and no serious functional or anatomical disturbances are produced. This raises the question as to how far the dema itself is responsible for the fatal outcome in cases of acute poisoning with the suffocant gases, and suggests that other factors, such as the increased viscosity of the blood, the obstruction to the pulmonary circulation, and the resultant cardiac weakness, may be of greater moment than the mere accumulation of fluid in the air spaces.

The demonstration that inert granular material and even bacteria can in great measure

be washed out of the lungs, opens new possibilities of experimental research along therapeutic lines.

ALWIN M. PAPPENHEIMER

COLUMBIA UNIVERSITY

SPECIAL ARTICLES

THE TAKE-ALL DISEASE OF WHEAT IN NEW YORK STATE

FOR nearly two decades plant pathologists have been interested in the possible introduction of the take-all disease of wheat into America. A detailed historical and bibliographic treatment of this and some related diseases of wheat has recently been published by Stevens.1 Conditions, believed to be due to take-all, have been reported from Oregon in 1902 and more recently (1919) from Illinois and from Virginia. However, the fungus Ophiobolus graminis Sacc. has not yet been reported from these localities in the papers which have come to the writers' notice. If the name of "take-all" be restricted to the disease with which Ophiobolus graminis is associated, there remains some doubt as to the reported occurrence of the true take-all in this country.

Early in July, 1920, the attention of Mr. R. G. Palmer, field assistant of the Department of Plant Pathology, was attracted to a small spot in a field of soft red winter wheat at East Rochester, New York. The plants within an area eight to ten feet in diameter were badly dwarfed and prematurely dead. In many cases secondary culms had been killed soon after their formation. On July 15 the diseased spot was brought to the attention of Dr. M. F. Barrus who brought specimens into the laboratory for examination. roots of the plants were rotted and usually broken near the base of the culm when the plants were uprooted. The lower internodes were dark or entirely blackened and enveloped by a dense sheath-like plate of thick-walled brown mycelium. This plate of mycelium was formed between the leaf sheath and culm, as

1"Foot-rot Disease of Wheat-Historical and Bibliographic,'' Natural History Survey, Ill. Dept. Registration and Education, Vol. 13, Art. 9, 1919.

described by McAlpine for Ophiobolus graminis. Perithicia in considerable abundance were found embedded in the leaf sheath and mycelial plate. Microscopic measurements of perithecia and ascospores agree very closely with those given by Saccardo for Ophiobolus graminis.

As soon as a determination of the fungus had been made steps were taken to determine the source of the infection and to completely eradicate the disease from the infected area. An inspection was made of the farm which had grown the seed for the past two years. No evidence of take-all was found on this farm or on any of a considerable number of others in the vicinity of the diseased field and elsewhere. The crop from an area forty feet in diameter was spread over the ground and gasoline was poured over the infected spot and vicinity. The whole was then burned over.

The writers are indebted to Dr. W. B. Brierly, of the Rothamsted Experiment Station, England, and Professor Et. Foëx, of the Station de Pathologie Végétale, Paris, France, for examination of the affected wheat. Dr. Brierly states that the disease is indistinguishable from the take-all as it occurs in England. Professor Foëx concludes that the associated fungus is undoubtedly a species of Ophiobolus. Saccardo lists two species of Ophiobolus as occurring on wheat, O. graminis Sacc. and O. herpotrichus (Fr) Sacc. The ascospores of O. herpotrichus measure 135–150 × 2-2.5 microns, practically double the spore length of 0. graminis. It has already been pointed out that the fungus under consideration agrees closely in spore measurements with Saccardo's 0. graminis. It is not intended here to settle the question of the pathogenicity of the Ophiobolus as it occurs in this country or abroad. However, both the fungus and the diseased symptoms with which it is associated agree in essential details with the take-all of wheat and Ophiobolus graminis as described in Australia, France and elsewhere.

CORNELL UNIVERSITY

R. S. KIRBY,

H. E. THOMAS

2 McAlpine, D., "Take-all and White Heads in Wheat," Victoria Dept. Agr. Bul, 9, 1904.

THE AMERICAN CHEMICAL SOCIETY.

XII

DIVISION OF PHARMACEUTICAL CHEMISTRY

Charles E. Caspari, chairman
Edgar B. Carter, secretary

Stability and chloramine antiseptics: JULES ВЕВІЕ.

Chemistry and pharmacology of the chloramines: CARL NIELSEN.

Colorimetric estimation of adrenalin: WILBUR L. SCOVILLE.

Improved methods for arsenic estimation: H. F. FARR.

The melting point and the determination of free salicylic acid in acetyl salicylic acid: L. A. WATT. Biological methods for digitalis assay: HERBERT C. HAMILTON.

Researches on hypnotics: E. H. VOLWILER. Researches on anesthetics: ROGER ADAMS. Wood alcohol and prohibition: CHAS. BASKER

VILLE.

Drug absorption in the intestinal tract: G. H. A. CLOWES and A. L. WALTERS.

Iodine telerance of the human body and iodine therapy: H. C. P. WEBER. A very unusual case of cure of tubercular meningitis is discussed. Only isolated instances of recovery from this disease are known in the literature. The cure was effected by dosage with extraordinary quantities of iodine, given as tincture with various albuminoses and fatty vehicles of administration. The maximum was 1 gram of iodine per day (equivalent to 0.033 g. per kg. body weight); the total equaled 12.35 g. over 22 consecutive days. No iodism was noted. The conclusions drawn were that (a) the maximum dose of I is not known, (b) the disturbing effects, iodism, are astonishingly small, or even absent, (c) therapeutic effects as bactericide, require piling up of I in the body, (d) that the disturbing effects of KI are often confused with the effects of I itself, (e) that aside from this, the methods of administering the I are of less significance. These conclusions seem to be worthy of, and require, verification.

The pharmaceutical chemistry and pharmacology of the chloramines: CARL NIELSEN. To obtain best results with the chloramines some knowledge of the chemistry of these products, particularly as regards incompatibilities, combinations and pharmacologic action, is essential.

Research on hypnotics: E. H. VOLWILER. History of hypnotics, soporifices, and sedatives.

Present day hypnotics, with comparative value and uses. Qualities desired in hypnotics and present research in this field.

Research on anesthetics: ROGER ADAMS. Former anesthetics and their uses and drawbacks. Transition from natural to improved synthetic products. Qualifications of a good anesthetic and how the problem is being solved.

Improvements in the methods for arsenic estimation: H. V. FARR. A very brief review of the methods in present use is given. In addition to this a variation in the Gutzeit method is outlined, whereby the preliminary preparation of the chemical in ordinary cases is eliminated. Sulphites, etc., are oxidized by bromine and the arsenic subsequently reduced by potassium iodide, both of these reactions being accomplished within the reaction cell while the test is going on, representing a very great saving of time. In addition to this some simple methods for removing metals which interfere with the Gutzeit test are outlined, thus rendering this method more widely applicable. gravimetric method for determining arsenic in the metallic form where this metal is present in considerable amounts is outlined. This is particularly applicable in cases where the simpler volumetric methods can not be used.

A

The colorimetric estimation of adrenalin: WILBUR L. SCOVILLE. Solutions of adrenalin are necessarily acid, if kept in stock, in order to preserve the activity. This acid has a marked effect upon the color produced. The official process is designed for the estimation of adrenalin in the dried glands, and will apply to these, but is not satisfactory for commercial solutions. A method is given which is applicable to both, and which the author considers preferable to the official process. It is based upon Krauss's method, using potassium iodate as the oxidizing agent and pure adrenalin as a standard.

Stability of chloramine antiseptics: JULES BEBIE. In order to assure the greatest possible degree of stability the chloramines must be produced with a high degree of purity. Investigation extended over period of one year indicates that chloramine-T in crystal and tablet form, by itself or when mixed with NaHCO, is stable. Aqueous solutions of chloramine-T alone or in mixture with Na,CO, or NaCl are also stable. Dichloramine-T in powder form begins to deteriorate after about three months. The crystallized commercial product, however, is stable for about 8 months, and after 14 months shows only very slight degree of

decomposition. Solutions of crystallized dichloramine-T in chlorosane are fairly stable for a couple of weeks. Halazone is fairly stable. Decomposition after one year amounts to about 3 per cent.

The determination of the melting point and free salicylic acid content of acetylsalicylic acid: L. A. WATT. A comparison of the methods in general use for the determination of the melting point of acetylsalicylic acid. The desirability of a uniform procedure is emphasized by the variation in the results obtained. For estimating the free salicylic acid content, comparison with a set of standards made from a mixed dye solution permits the close approximation of the violet color produced by the addition of ferric chloride to the acteylsalicylic acid solution.

The biologic methods for digitalis assay: HERBERT C. HAMILTON. The author questions the relevancy of certain criticisms of biologic assay on the ground that such an assay is limited in its scope. Biologic assays are not to decide the question of dosage nor the applicability of the drug for any particular purpose nor does a biologic assay merely record that a drug will kill an animal and permit the inference that the drug is standardized. A biologic assay is a comparison of the sample in question with a similar preparation of known activity. The comparison of effects is made on some test animal which responds to the action of the drug in so characteristic a manner that the effect is measurable. The proposed methods for digitalis with their advantages and disadvantages are described at length in order to emphasize the scope and limitations of the biologie assay of the digitalis series.