Jtily 31, 1879J 



NATURE 



325 



M. Dionys Szabd has made the character of the acid 

 in gastric juice a subject of research (vol. i. p. 140), and 

 has ascertained that it consists of both hydrochloric acid 

 and lactic acid, analogous to that produced by the souring 

 of milk. As hydrochloric acid is the more powerful 

 corrosive and solvent agent, it is natural to expect it to 

 be present in larger quantity than lactic acid in the 

 stomach of the dog, which requires it to bring fragments 

 of bone, &c., into solution. In certain dyspeptic cases 

 hydrochloric acid is wanting, hence, probably, the dys- 

 pepsia, owing to lactic acid alone not being sufficient to 

 bring the food into solution. It is probable that the 

 lactic acid is produced from the albuminous constitu- 

 ents of food by oxidation, and that it acts on the salt 

 which we take with our food, forming lactate of sodium, 

 and liberating hydrochloric acid. Chemical decompo- 

 sitions of this nature, the converse of what happens 

 in laboratory experiments, appear to be greatly favoured 

 by dialysis through colloidal membranes, such as the 

 walls of the ducts of the mucous membrane of the 

 stomach. 



Prof. Richard Maly (vol. i. p. 174) has made an attempt 

 to explain the phenomenon of inverse chemical reactions, 

 occurring under the influence of diffusion, with regard to 

 the formation of hydrochloric acid. Prof. Graham, in his 

 well-known researches on diffusion, showed that hydro- 

 chloric acid is the most diffusible of all liquids ; that if a 

 jar be filled with it, and carefully immersed in water, 

 taking care not to mix the acid with the water, more hy- 

 drochloric acid escapes in a given time than is the case, 

 under similar circumstances, with any other liquid. Now 

 it is an ascertained fact that a weak acid can replace a 

 strong one to a small extent, provided the weak acid is 

 present in large quantity compared with the strong one. 

 This replacement proceeds to a given point, when balance 

 sets in, and the reaction goes no further, owing to the 

 strong acid being liberated in such famount as .to check 

 any further decomposition, provided no disturbance takes 

 place. But in the case of lactic and hydrochloric acids in 

 the stomach, disturbance does take place, owing to the 

 more rapid diffusibility of hydrochloric acid through the 

 walls of the ducts. The hydrochloric acid is constantly 

 being removed as it is formed, and the sodium chloride, 

 or common salt, is continually in process of decomposi- 

 tion by the lactic acid. Hence the presence of hydro- 

 chloric acid in gastric juice. This decomposition is also 

 effected by what is generally called "neutral sodium 

 phosphate," which, although it has a faint alkaline reac- 

 tion on litmus paper, yet, in a chemical point of view, is 

 an acid substance, for it still contains hydrogen replace- 

 able by a metal. 



Dr. O. Lassar (vol. i. p. 165) contributes a paper on 

 irrespirable gases. Every one who has visited a vitriol 

 work knows the insufferable feeling of choking produced 

 by the fumes of the evaporation-chamber, and even those 

 who have not had that opportunity must occasionally have 

 experienced the disagreeable sensation of breathing the 

 fumes of burning sulphur from a sulphur match. This 

 choking sensation seems not to be felt by animals ; it is 

 due to spasm in the glottis and involuntary contraction of 

 the vocal chords. The object of Dr. Lassar' s experiments 

 was to ascertain whether such acid fumes are absorbed 

 by the lungs, conveyed into the blood, and passed out by 

 the urme. For this purpose he exposed rabbits and dogs 

 to the dense fumes of sulphuric acid for more than an 

 hour at a time, and examined the urine carefully for that 

 acid. It was invariably absent, showing that the acid is 

 not absorbed by the lungs. It was curious to remark that 

 on exposure of an animal to nitric acid vapour of such 

 strength that the hair, and even the membrane of the 

 lungs, turned yellow, the animal did not suflfcr in health, 

 and that the only effect of acid fiunes in air is to diminish 

 the proportion of 6xygen. This explains what has often 

 been wondered at— that workmen in the chlorine cham- 



bers and sulphuric acid evaporating-chambers are not 

 injuriously affected by the acid fumes. 



William Ramsay 



GEOGRAPHICAL NOTES 



The special committee appointed by the International 

 Meteorological Congress at Rome for the promotion of 

 expeditions to the Arctic seas charged with making syn- 

 chronous meteorological and magnetic observations, will 

 meet at Hamburg on October i next, in order to arrange 

 details and to discuss the means of arriving at the object 

 aimed at. Preliminary steps in this direction have, as 

 our readers are doubtless aware, been taken by Count 

 Wilczek and Lieut. Weyprecht. 



On August 7 next a century will have elapsed since 

 Karl Ritter, unquestionably the greatest geographer of his 

 time, was born at Quedlinburg. 



In the last issue of the Colonies and India the attention 

 of members of the Alpine Club is directed to the mountain 

 peaks of the West Indies. In the Blue Mountains of 

 Jamaica, for instance, views can be obtained which cannot 

 be surpassed in the world. Many of these mountains 

 have been, as yet, untrodden by the foot of man, and 

 they offer a wide field to the student of natural history as 

 well as the practical explorer. In the Island of Dominica, 

 again, there are opportunities for exploring mountains 

 which are hardly, if at all, known. An expedition under 

 two Englishmen has lately scaled for the first time one of 

 the peaks, known as Morne Trois Pitons, situated to the 

 north of Roseau. The heights of these peaks are 4,528, 

 4,552, and 2,672 feet respectively. The foot of the centre 

 piton was found to be at an elevation of about i,Soo feet. 

 For a considerable distance the party were able to follow 

 a wild-pig track, but they had to leave this and cut their 

 way through dense vegetation and scrub. On reaching 

 the summit they found it to be nearly flat, and covered 

 with impenetrable vegetation. This curious plateau was 

 estimated to be about ten acres in extent. 



The new number of the Belgian Geographical Society's 

 Bulletin publishes reports from M. Cambier and Dr. 

 Dutrieux on the march of the first Belgian African expe- 

 dition from Mpwapwa to Tabora, in Unyanyembe. These 

 are accompanied by a sketch-map of the country between 

 the East Coast and Lake Tanganyika, on which the route 

 of the expedition is laid down. 



A GOOD harbour is stated to have been discovered near 

 Point Parker, in the Gulf of Carpentaria, which will 

 probably be of service in the development of that part of 

 Australia. 



The Coreans are as little given to leaving their own 

 country as the Japanese used to be, but we learn from a 

 Shanghai contemporary that there appears to be a little 

 colony of them forming in the neighbourhood of Chin- 

 kiang, for, in addition to the usual ginseng traders, there 

 are now there several well-dressed Coreans having the 

 appearance of the better class of officials. They wear 

 slate-coloured garments as a sign of mourning for the 

 Queen. 



The new number of Zi* G/i3&' contains M. Veniukof's 

 account of geographical work in Asiatic Russia during 

 1878, and a paper on the Sahara. 



The last Bulletin of the Socidtd de Gdographie Com- 

 merciale of Bordeaux has a long note on French estab- 

 lishments in India, which will be found useful in supplying 

 information on a subject respecting which the world at 

 large knows but little. 



The just published number oiLes Annalesdc I'Extreme 

 Orient contains the continuation of Dr. Harmand's notes 

 on Khmer monuments, and of the Marquis de Croizier's 

 essays on Indo-China, based on Dr. Bastian's investi- 

 gations. 



