December 13, 1889.] 



SCIENCE 



401 



River Drainage," by G. W. Howell, C.E. ; " The Improvement of 

 Sanitary Conditions in the Health and Pleasure Resorts of New 

 Jersey," by Dr. Henry Mitchell ; " The Climatic Treatment of 

 Gastro-intestinal Diseases in Children," by Dr. Boardman Reed ; 

 " The Need of Medical Officers in School Districts," by Dr. G. F. 

 Wilbur ; " Physical Culture in the Schools in its Hygienic Bear- 

 ings," by Professor James M. Green ; " The Relation of Conduits 

 to the Healthfutness of Water," by Dr. W. K. Newton ; " Tuber- 

 culosis," and "Typhoid-Fever in Munich," by Professor S. G. 

 Dixon of the University of Pennsylvania ; " The Present Special 

 Sanitary Needs of our Cities," by James C. Bayles, formerly presi- 

 dent of the New York City Board of Health. The annual address 

 by the president was on " The Thermometry of Hygiene." 



High Altitude Treatment of Phthisis. — Tyson offers 

 certain considerations on this topic from climates marked by (i) 

 extreme purity of the air, (2) aerial rarefaction, (3) low relative 

 humidity, and (4) immunity from wind, fog, and miasmal emana- 

 tions. The cases sent to such climates should be carefully selected. 

 No case should be sent in which there is senile change, laryngeal 

 ulceration, gout, rheumatism, organic nerve-disease, or hysteria. 

 When there is no marked emaciation, severe pyrexia, or kidney 

 complication, Mr. Tyson finds that the cases do well. An impor- 

 tant rule is that the patient should live continually in the chosen 

 place, and not return, even for short visits, to lower altitudes. 

 This length of time, as we learn from the BrooUyn Medical 

 Journal, he believes should be fully two years. Cold, dry air is 

 stimulating. It is detrimental to all fungous growth. The secre- 

 tion from a cavity has a tendency to dry up. Its rarefaction in- 

 creases the number of respirations, and has a considerable influ- 

 ence in permanently expanding the lungs. Slight oozing of blood 

 from the mouth, nose, and throat is common when patients first 

 arrive. It may be that the mucous membranes near the surface of 

 the body become dry, and there may be blood stasis, especially 

 when the air is cold. In the lungs, however, the supply of watery 

 fluid is so great that dryness is impossible, and, at the same time, 

 the air is warm before it reaches the lungs. The removal of watery 

 vapors would even relieve the congestion without bleeding. It may 

 be, however, that the diminished air-pressure tends to draw the 

 blood to the surface, and so cause the bleeding. Mr. Tyson finds 

 that these slight hemorrhages do not harm, and that the mem- 

 branes soon become accustomed to the changes in the air. 



The Acids of the Stomach. — There is no doubt that the 

 chief acid found in the stomach during natural digestion is free hy- 

 drochloric acid. According to The British Medical Journal, this 

 has been abundantly proved by Bidder and Schmidt, and numerous 

 observers succeeding them. The methods used are, however, too 

 long and too complicated to employ in clinical work. The physi- 

 cian wishes to know what, in a particular case of disease, are the 

 chemical changes going on in the stomach ; whether, for example, 

 hydrochloric acid is present, as well as pepsin and organic acids. 

 Now, in the examination of the contents of a diseased stomach, 

 three forms of acid may be present, — hydrochloric acid, a mineral 

 acid ; organic acids, such as lactic acid, butyric, etc. ; and, thirdly, 

 acid phosphates. It is chiefly of importance to determine the 

 presence of hydrochloric acid and of organic acids. Many methods 

 have been proposed for doing this : they consist mainly in testing 

 the effect of the stomach contents on various colored solutions. 

 Thus a solution of methyl-violet is decolorized by hydrochloric 

 acid, so that, if this re-action is obtained, the free acid is present in 

 the liquid tested. Lactic acid turns the violet a dirty yellow. 

 Tropseolin also is turned deep reddish-brown by free hydrochlo- 

 ric acid. Unfortunately these tests, simple as they appear, are not 

 accurate, since the re-actions are interfered with by the presence of 

 peptones and of some neutral salts ; and, as these are usually pres- 

 ent in the stomach contents, no reliable results can be obtained by 

 using methyl-violet and tropKolln. They have been superseded by 

 congo-red, which is turned blue by free hydrochloric acid, and by 

 a. solution of vanillin and phloroglucin in alcohol, which is turned 

 a deep red by the same acid. These simple clinical tests are, how- 

 ever, rendered useless by the fact that they are interfered with by 

 the presence of peptone, ammonium salts, chlorides, and phos- 

 phates. In the present state of our knowledge, therefore, there is 



no reliable indicator for the presence of free hydrochloric acid in 

 the stomach contents. Other methods which may be used are too 

 complicated for clinical use. Thus ether has the property of dis- 

 solving organic acids from a liquid, leaving the mineral acids in so- 

 lution. It may thus be used for separating the lactic, butyric, and 

 other acids from the hydrochloric acid ; and if, in a liquid obtained 

 from the stomach, it is found that ether removes the whole of the 

 acids present, it may be concluded that no free hydrochloric acid 

 is present. In many cases this conclusion would be an important 

 one as a clear indication for a line of treatment. Dr. Leo has 

 lately published a new method for the indication of free hydro- 

 chloric acid which may prove useful. Leo considers the case 

 where it is only a question of the presence of free hydric chloride 

 and of an acid phosphate. To a few drops of the stomach con- 

 tents a pinch of carbonate of calcium is added. If the acidity, as 

 tested by litmus-paper, disappears, only a free acid is present ; but, 

 if the liquid is still acid after the addition of the chalk, an acid salt 

 is present. If, moreover, organic acids be present, they must be 

 first removed by shaking with ether before the chalk is added. It 

 does not seem that Leo's method is one that can be applied at the 

 bedside, because the detection of free hydrochloric acid is chiefly 

 requisite in those cases in which organic acids are also present, as 

 in cases of dilated stomach. At present, indeed, a ready method, 

 suitable in clinical practice for the detection of free hydrochloric 

 acid in organic liquids, is a desideratum. 



Cholera in Persia. — A correspondent of \.\\.^ Bulletin Med- 

 ical, writing from Teheran, says that cholera in a virulent form 

 exists throughout the valley of the Euphrates, and it is feared that 

 it will become epidemic in Persia. 



Cremation in Paris. — The cremation furnace in Pere-la- 

 Chaise Cemetery, in Paris, is now complete, says The Medical 

 Record, and the prefect of the Seine has approved the scale of 

 charge to be enforced thereat. The charge for the use of the cre- 

 mation furnace is to be fifty francs, which sum includes the keeping 

 in the columbarium of the funeral urn containing the ashes for a 

 period of five years. 



Bicarbonate of Sodium in Milk. — Hitherto it has been 

 deemed permissible to add soda bicarbonate to milk to assist in 

 its preservation, but now the Council of Hygiene of the Seine has 

 condemned the practice as one of danger. The transformation of 

 milk-sugar into lactic acid, in milk so adulterated, gives rise to a 

 lactate of soda which is purgative, and frequently a source of al- 

 most uncontrollable diarrhoea in infants : consequently the council, 

 in its bulletin, decides that " soda shall no longer be permitted in 

 milk, which is an aliment of the first order, and very often prescribed 

 for invalids and children." 



ELECTRICAL NEWS. 



The Transmission of Visual Images by Electricity. 



A French electrician endeavors to solve the question of seeing 

 at a distance by electricity, by means of a combination consisting 

 of a selenium cell, a gas-telephone, and revolving mirrors, forming 

 a special apparatus which he designates a " phoroscope," and which 

 he discusses in La Luniiere Electriqice as follows. 



The question of seeing at a distance by electricity is governed by 

 the two following fundamental principles. In order to get the im- 

 pression of the form, outlines, and details of one or several objects, 

 it is not necessary (i) that the eye should receive all the rays pro- 

 ceeding from it ; (2) that it should receive, at the same time, the 

 luminous rays necessary for vision. 



Some very simple examples will demonstrate the first principle. 

 We can see an object very clearly through wire gauze, and the 

 image is perfect if the interstices are large and the wire fine. Carpets 

 and mosaic seen at a certain distance do not seem to be formed of 

 a number of parallel lines, nor by the juxtaposition of little stones. 

 An engraving, a picture, or especially a chromo-lithograph, show 

 at a distance no discontinuity in the work, although the engraving 

 is composed of lines, and the chromo-lithograph of separate little 

 dots. We see thus that it is possible to have a sufficiently clear 



