CHEMICAL POWS, } Anthracen Testing. 1876. 177 In the morning the water was drawn off from the tubes ON ANTHRACEN TESTING. by a pipette having a long fine point, and each transferred to a small test-glass. A drop of each solution was then By DR. FREDERICK VERSMANN. taken out by a clean glass stirring rod and spread across pieces of blue litmus paper in a series of lines side by In a paper “On Anthracen and Alizarin," read before the side with each other, the intensity of redness thus pro- Society of Arts in March, 1874, I ventured to express my duced by the acids dissolved by the water compared, and opinion that the quinon test was not trustworthy, because the results noted. it did not represent true anthracen convertible into alizarin, Fifth.--Five grains of a moderately strong solution of and also because the stipulated corre&ion, equal to 1 per ferrocyanide of potassium were then added to each water cent, made the whole process illusory. solution above mentioned, the mixture stirred, and left for At that time I stood alone in my opinion, but it is now four hours, when the amounts of the precipitates of ferro perfectly well known among manufacturers and buyers of cyanide of copper were observed comparatively and the anthracen that the quinon test does not always indicate results noted. The results of these observations I have the exact and true value of the merchandise; and even arranged in tabular form. Messrs. Meister, Lucius, and Brüning, who first proposed (To be continued.) the test, now acknowledge its inaccuracy by issuing in last week's CHEMICAL News (vol. xxxiv., p. 167) a new and improved method. This new test differs from the previous one merely by an PYROLOGY, OR ANALYSIS AND SYNTHESIS increase of the oxidising agent-chromic acid and its solBY THE BLOWPIPE. vent acetic acid and water-and by the treatment of the By MAJOR ROSS, late R.A. quinon with fuming sulphuric acid instead of with potas sium permanganate, and subsequent volatilisation of the (Continued from vol. xxxiii.. p. 3.) remaining quinon. The publication of this " new and improved method” (11.) The fact may have been noticed, with regard to induces me to collect the results of prolonged investigathe Scientific Loan Exhibition at South Kensington, that tions on the subject, which, although not yet brought to a three-fourths of the apparatus, &c., there displayed are final conclusion, may tend to throw some light on the foreign, and that a great part of the remaining fourth, nature of the products obtained, and I am the more although the property of English “ Manufacturers,” has inclined now to publish my experience, because more than in reality been produced in Paris, Berlin, or some other six months ago I tried tbe sulphuric acid myself, but found French or German town, while Sir W. Thomson, Sir. J. it neither satisfactory nor practical. In fact it was exa&ly Hawkshaw, and others less celebrated, who have lately the failure with sulphuric acid which induced me to follow arrived from America, are unanimous in the opinion that, up the subject in a different direction, and, as I believe, unless we are careful, the Americans will shortly pass us with more satisfactory results. in those manufactures of which we have hitherto been After boiling a sample of anthracen with chromic acid most proud. In short, look on the matter as we may, solution, and allowing the mixture to stand for hours, deny the fact as we will, it seems doubtful if nationally long, well-defined crystals separate, and on adding water England occupies more than the third place in scientific a further separation takes place, not in the form of cry. Europe. stals, but of an amorphous powder. The product collected (12.) The reason of this appears that, like everything on the filter is always a mixture of crystals and powder, else, scientific knowledge is made a mere matter of barter part of the last of which is again removed by potassium in England. Only rich men can here afford to do anything permanganate and potassium hydrate. original in the way of physical or chemical experimenta. This observation induced me to collect the crystals and tion. powder separately, and to ascertain their nature by practi(13.) Here then, briefly, is what the blowpipe will do cal tests applicable for commercial analyses. As such I for a student who takes it up with due appreciation :- adopted, above all, the melting- and solidifying-points, (a) The necessary apparatus is, or ought to be, cheapest and then the action of potassium permanganate and potasof the cheap, even the balance required for quantitative sium hydrate. analysis being the smallest and cheapest kind made. The determination of the melting, and solidifying. (6) Accurate observations can be made so rapidly that point I look upon as most important and valuable, and I even the public teacher in chemistry and physics can thus can only express my surprise that it has not been intro. most beneficially employ his little leisure. (c) The field duced long ago, especially as it formed so important a of observation is almost entirely unoccupied, so that the part in the alcohol and bisulphide test. disciple, unencumbered by the terrific terminology of che- I have collected in the following table some results from mistry, may after a short time bring contributions to a great many, which fairly represent commercial anthra. physical science really worthy of her acceptance; while cen from the lowest to the highest percentage. The first geology and mineralogy will after a time acquire a new column gives the percentage of quinon actually obtained, zest from such examinations. (d) If our manufacturers i.e., without correction; the second and third columns give were only equal to the Germans or French, a traveller's the crystals and powder separately; and the last column apparatus might be made for a few shillings, in a leather the number of drops of 5 per cent potassium permanganate case, which would roll up and go into the breast pocket of solution required to leave a distinct colouration after proa coat, enabling the investigator to start at a moment's longed boiling of each of the three products. notice for the country or abroad. I shall try to induce As to the operation itself, the first result was obtained Messrs. Griffin to make up such a case of blowpipe by the usual test with appendix. In the separation of necessaries, and to sell it as cheaply as possible. crystals and powder the solution was allowed to stand (14.) All sciences are so linked together that a correla. over night; the crystals were then collected on a small tion can be shown to exist even between two of the most filter, and the solution allowed to run off to the last drop, apparently widely separated. Few, for instance, would before the crystals were washed with water, until the filter suspeo that the political economist could derive any and filtrate were perfeâly colourless. The filtrate was benefit from the study of blowpipe analysis, and yet the then diluted to 600 c.c., and after two hours' standing the case of the tumble-down barracks and public buildings all powdery precipitate was also collected on a filter ; both over Northern Indian, publicly stated, without denial, to crystals and powder were then treated with potassium have cost the Government £40,000,000, between the years permanganate and potassium hydrate. 181-75, is one in point; but the account of this must be I have long adopted an increased addition of water, but reserved for the next paper. for a different reason than the one now stated by Messrs. Drops of 5 p.c. Potassium 6 2 5 9 4 10 276 280 279 178 Anthracen Testing: Oct. 27, 1876. , Anthraquinon Test. Meister, Lucius, and Brüning. I have always doubted the accuracy of adding i per cent of quinon, supposed to be retained in solution, and I have satisfied myself on that Crystals and point by actual experiment. I have frequently evaporated Powder Mixed. Crystals. Powder. the green solution to perfect dryness, and exhausted the dry powder with benzol and alcohol, but I have never succeeded in separating real quinon. The larger quan283 278 tity of water merely separates the powder more completely, 1. 114 275—279 6:6 272—275 4:8 not at 300 15 3 20 which no doubt accounts for the increased quantity of 280 278 potassium permanganate used with the powder. 274 2. II49 274–277 9*4 274–276 297 264–269 The conclusions drawn from this table, I may state as 10 3 12 follows, viz. :- 1. The total of crystals and powder in all cases very 3. 14'2 273-275 10'2 272-275 4'0 273--274 nearly agrees with that of the mixture ; no loss is 278 279 270 incurred by the separation. 4. 142 270-274 92 273-276 5'3 272—271 10 4 16 2. The melting- and solidifying-point of the mixture, 278 278 273 i.e., of the usual test, is mostly suspicious, in many 5. 1592 270-274 10'3 272-275 584 271-272 cases a direct indication of undoubted impurity of the quinon. 278 6. 15'2 274–275 10ʻ2 274–276 4:6 270-275 8 3 10 3. The melting- and solidifying-points of the crystals alone are much more uniform ; the product is pure 276 278 quinon. 7. 16'0 270—273 12'5 274–276 3.6 not at 300 25 3 28 4. The powder in almost all cases is no quinon at all; 278 277 278 in eleven cases out of thirty it does not melt at 8. 16°2 274–276 11:6 273—275 562 266-272 12 4 12 300° C., but blackens and remains solid ; in eleven other cases the mean of the two points is below 270 277 270° C., and in several of the other cases the 9. 17.8 266-268 9:8 273-275 7*7 not at 300 27 4 27 melting- and solidifying points were only partial or 277 indistinct at the points indicated. 0. 18'2 271–275 14'2 275—276 3.9 not at 300 20 4 24 5. The effect of potassium permanganate is uniformly 278 277 very trilling upon the crystals, very considerable II, 20*2 274–276 16'3 273—275 347 not at 300 upon the powder, and exactly the same is the case 9 3 10 with potassium hydrate; while the mixture often 277 277 imparts distinct colouration to the solution and 12. 20°6 273--275 17.8 275–276 2:6 not at 300 15 4 14 becomes itself lighter in colour—from orange to 277 281 276 pale straw-yellow-the crystals alone scarcely show 13. 22.0 273—275 1863 273—277 4'0 266-271 16 5 15 any change, but the powder invariably gives a 270 276 260 strong colour to the solution. 14. 23'3 266—268 15'1 272—274 80 256-258 6 2 6 6. While the crystals may safely be taken as pure quinon, 278 the question arises whether the powder always 278 278 15. 23.8 274-276 199 276—277 3:6 2704-274 consists of nothing but impurities, or whether it still retains some quinon, as in a few cases the 280 280 271 melting point tends to indicate. 16. 26°4 274–277 22.1 276—278 4*2 261–266 10 3 II 277 278 Although I have not completed my experiments in that 270 17. 27'0 273—275 20.8 274–276 6.1 260—265 direction, I shall shortly be able to definitely settle this point by practical tests. But I think it advisable not to delay the publication • 30'2 268—269 249 274--274 53 256—260 8 3 10 of my results hitherto obtained, as I am satisfied of the 273 277 259 correctness of separating crystals and powder and of its 19. 30'5 267—270 24:6 273—275 5.6 253–256 10 4 14 undoubted advantage over the other known test. 278 278 I have meanwhile brought my test into practical work20. 34:8 268—273 30'0 276—277 4:6 not at 300 22 6 20 ing by taking the crystals as pure quinon, and by con280 280 sidering the powder as valueless impurity in all cases 21. 3665 274--277 30:6 274–277 567 not at 300 16 5 18 where the melting- and solidifying-point is below 270° or above 280°, and by adding the powder to the crystals 280 281 as quinon whenever these two points range between 22. 37*2 274–277 33'1 277-279 4'o not at 300 12 5 16 270° and 280'. 271 275 262 This compromise, for such I admit it to be at the best, 23. 39*9 267-269 34'0 273—274 5.8 258—260 8 2 8 has given general satisfaction to those who had it tried; 278 278 276 and although I hope in a short time to complete my inves24. 4107 276—277 3863 276—277 3.3 264-270 10 3 12 tigation, I meanwhile propose the above test, which, briefly 278 276 stated is as follows: 270 25. 45'2 270—274 41'1 274–275 4'0 266—267 Boil i grm. of the sample for four hours with 15 grms. 9 3 10 of chromic acid dissolved in 10 c.c. of glacial acetic acid 268 275 246 and 10 c.c. of water; allow it to stand for twelve hours, 26. 49'5 268—268 40*9 271–273 897 250-248 10 2 10 collect the crystals on a small filter, and let the solution 280 280 run off to the last drop; then wash the crystals with 27. 52'5 272—276 47*9 274—277 4-7 not at 300 16 4 16 boiling water till the filter and filtrate are quite colourless, 279 280 dilute the filtrate with water to 600 c.c., let stand for two 28. 56'3 275—277 539 274–277 2:6 not at 300 16 3 16 hours, and collect the powdery precipitate on a filter and 280 wash well. Then treat both crystals and powder275 250 29. 60'0 270—275 554 273-274 4'2 240—245 separately, of course—with potassium permanganate and 12 2 14 potassium hydrate as hitherto, collect each on a double 282 280 285 filter, dry and weigh, but do not add the correction; then 30. 68o5 272—277 63'2 276–278 5'I 287–286 10 3 12 take the melting, and solidifying-point of both. The 8 2 7 12 2 14 179 0 % " = 2'02 ash ,} Practical Chemistry in the University of Virginia. Oct. 27, 1876. crystals to be taken as pure quinon, the powder also to be = 2.0 per cent. This ash was dissolved in a very small taken as quinon if melting- and solidifying-points range quantity of sulphuric acid, the solution diluted, and the between 270° and 280°, but as valueless impurities if these iron (easily diluted in previous quantitative experiments) two points are below 270° or above 280°. reduced to a ferrous salt by a minimum of pure zinc, This test is more reliable, and more just to buyer and determined by a much diluted solution of potassium perseller, than either the usual quinon test or the one now manganate. The result was o‘00859 grm. of Fe proposed by Messrs. Meister, Lucius, and Brüning. per cent of the ash. My experience as to the action of sulphuric acid upon No. 2--Skin from the outside of the thigh of a Negro crude quinon is as follows. woman, aged about 40 years, born in Virginia.- The (To be continued.) cuticle was rather more completely separated from the true skin than in the last instance. The same trea ment was applied. 2 grms. of material dried at 100° C, left 0'056 grm. of ash 2.8 per cent, and in this there was NOTES OF WORK BY STUDENTS OF present o'00142 grm. of Fe = 2.54 e cent of ash. PRACTICAL CHEMISTRY These specimen of negro skin were obtained from the IN THE Anatomical department of the University of Virginia ; for LABORATORY OF THE UNIVERSITY OF those from white subjects, which at the time were not available here, we were indebted to my friend Dr, Souchon, VIRGINIA. of New Orleans. No. V. No. 3.—Skin from the anterior surface of the thigh of a Communicated by J. W. MALLET, white man, 40 years of age, born in Maine.—The epiderProfessor of General and Applied Chemistry in the University. mis was taken off pretty clearly, with very little of the true skin remaining attached to it. Same chemical treatment (Continued from p. 169.) as above. 18 grms. of the dry cuticle gave 0-207 grm. of I'15 per cent, in which was found Fe = 0.00235 grm. I'13 per cent of the ash. Negro Skin. By Dr. F. P. FLOYD, of Tazewell Co., thigh of a white man, aged 45, born in France.-Cuticle taken off as clearly as possible and treated as before. being a product of the alteration of the colouring matter Strips of cuticle with a little of the outer layer of true of the blood. skin attached were taken from a negro cadaver, and As regards the local distribution of the pigment granules having been well washed with water and alhohol, and there seems to have been hitherto a little confusion of with ether to remove fatty matter, were cautiously scraped statement. In the older books they are said to occur in with the blunt edge of a scalpel, in order, if possible, to the “rete mucosum" between the epidermis and cutis, and, loosen up the pigment granules and permit of their separa- although the existence of such a distinct middle layer of tion and purification by mechanical washing. A very the skin is no longer admitted and the name for it has little examination with the microscope, however, showed therefore disappeared, the same general idea seems to that this could not be done without breaking up the whole remain that the colouring matter belongs to the subsubstance of the cuticular tissue, and mixing its débris cuticular portion of the skin, and hence impliedly that it with the granules, which therefore could not be obtained does not extend outwards into the cuticle itself. I have in a state of purity. By seleđing only those parts in found too in the Southern States many physicians under which there was most pigment, and cautiously treating the impression that a blister produced upon the negro these as above, enough of it was procured with but little skin is white, or at any rate much lighter in colour than admixture to establish the following points. The colouring the surrounding surface. From the chemical inalterability matter is insoluble in water, alcohol, and ether. It is of the pigment, as above ascertained, this would seem also undissolved by treatment with dilute acid or alkaline very unlikely; a few observations were therefore made solutions. It is but slowly attacked by the strong acids, upon the subjeđ. even by concentrated nitric acid. Chlorine, especially in Thin vertical sections of negro skin from the cadaver the presence of alkalies, completely destroys it. Heated were made, and these under the microscope showed brown for some time with a strong solution of sodium hydrate it and black granules to the very edge of the cuticular suris gradually dissolved. and the solution when diluted face, which, however, seemed to have been partially yields a partial precipitate on neutralisation with an acid. removed, probably by post mortem softening and the In all these respects the behaviour of this substance washing which the subject had received. agrees perfectly with the melanin of the eye. A few extremely thin horizontal shavings were therefure In order to get an approximation to the quantity of iron taken off with a razor-like scalpel from the arms of two present, as the pure pigment could not be had, compara- living negroes, man and woman respectively, drawing no tive experiments were made with the cuticle of black and blood and cutting with the blade so slanted as to thin off white subjects with the following results : one side of the shaving to nothing. These sections No. I. -Skin from the outside of the upper arm of a showed under the microscope the pigment granules Negro man, aged about 50 years, born in United States. through the whole of the cuticle, though less easily obThe cuticle and a little of the outer portion of the cutis served among the epidermic scales than in the less dense were taken, washed with water and alcohol, macerated in structure beneath in which the flattening of the cells had ether for twenty-four hours to remove fat, and then dried not yet gone so far. Finally, one or two small blisters at 100° C. 21:249 grms. of the dry material on being were produced by very small drops of a solution of can. carefully and completely burned lest oʻ424 grm. of ash tharidine, and the raised cuticle from these gave quite th a Bealey 33.62 ON THE 180 {CH , Oct. 27, 1876. same result under the microscope. The blisters them No. Analyst. For 200 parts Hg we have of s. selves before being punctured were distinctly brown to the Neumarktel Klaproth 33'52 naked eye, while no doubt the side light which comes in 2. Japan 34.90 through the projecting mass of transparent colourless 3. John fuid has a tendency to produce the impression of lighter 44.64 4. colour upon the observer. Westphalia Schnabel 31.50 5. Wetzlar There can be no doubt, I think, that the brown or 44'42 California 32.82 black pigment originates in the outer layer of true skin, 7. Idria (hepatic) Klaproth its production being probably connected with the loss of vitality of the cells, and that it accompanies these cells instead of 32-o, as demanded by theory. In the third and all the way to the surface, where it is mechanically re fifth of these analyses native sulphur was probably moved by disquamation. The chemical modification of present. (To be continued.) the red colouring matter of the blood corpuscles may possibly be in some way dependent on feebleness of circulation in the superficial capillaries, to which would seem to point a number of facts as to the diseases to REPORT which negroes are specially liable, as well as their extreme sensitiveness to low atmospheric temperature, a severe frost which would be little more than bracing to a white DEVELOPMENT OF THE CHEMICAL ARTS man often fairly benumbing all their faculties, bodily and DURING THE LAST TEN YEARS.* mental. By Dr. A. W. HOFMANN. (4.) Analysis of Cinnabar from Oregon. By C. W. (Continued from p. 167.) DABNEY, Jun., of Hampden Sidney College, Virginia. A specimen of cinnabar in calcite from the land of Dr. Chlorine, Bromine, Iodine, and Fluorine. F. C. Horsley, near Canyon City, Oregon, when pul. verised and treated with dilute hydrochloric acid, gave off By Dr. E. Mylius, of Ludwigshafen. sulphuretted hydrogen. This fact seemed to make it We may here also mention the bromiferous artificial worth while to analyse the specimen carefully, and it was saline mixtures prepared in imitation of the salts obtained placed in Mr. Dabney's hands for the purpose. It was from mineral springs.t At Vienna the mother-liquors and found that after being thus treated with acid it gave, on their salts of Kreuznach, Kæsen, Wittekind, &c., were heating in a closed tube, a small sublimate of sulphur, and exhibited by Frank, and by the United Manufactures of the residue on being again treated with hydrochloric acid Leopoldshall. Finally, we must mention the arrangegave an additional amount of sulphuretted hydrogen, ments adopted for preserving the workmen from the inwhilst iron was found in solution. jurious action of bromine. It appears, in fact, that when A specimen freed from the calcite gangue by very these are applied no danger to health is to be appreweak acetic acid was dried, weighed, and acted on with hended. In the selection of workmen it is primarily hydrochloric acid of 6 per cent real acid. The sulphu- essential to see that they have well-developed respiratory retted hydrogen given off was collected as sulphide of organs, and are free from any predisposition to asthma silver, and its amount determined. The residue was then and catarrhal affections. The use of spirituous liquids analysed by ordinary methods, adding in the small quan must be striąly interdicted, as the irritability of the tity of iron which the hydrochloric acid had taken up. dangerous. On the other hand, a generous diet is recom; mucous membranes which they produce is exceedingly The results were : mended, and especially the abundant use of fatty and Mercury.. 78.42 mucilaginous articles, butter, bacon, &c. 0:54 As it appears that the workmen do not make use of the 13:59 respirators with which they are furnished, and at most Iron 4'09 merely tie a cloth over the mouth and nose when decantSilica 3:06 ing large quantities of bromine, the most important point Oxygen (by difference) 0:30 is to secure an efficient ventilation in all parts of the works. By attention in this respect, combined with the From the behaviour of the mineral with hydrochloric practicable to maintain the health of the workmen at above-mentioned dietetic regulations, it has been found acid and on heating it may fairly be concluded that part Stassfurt, during the eight years of the existence of the of the iron exists as ordinary iron pyrites and part as bromine manufacture, so long as they refrain from the use magnetic pyrites. If now the sulphur be distributed, of spirituous liquors (Frank). first, to mercury to form HgS; second, to the extent of that evolved as H2S, to iron to form magnetic pyrites recent excursion to Stassfurt to visit Frank's bromine (The editor of this Report has had opportunity during a (assuming this to be Fe,S8); and, third, the residue, to works, and, it may be, permitted him to add certain reiron enough to form iron pyrites, the rest of the iron being sults from his own observation in order to complete what assumed present (as some visibly was) as ferric oxide ; has above been given in bold outline.) the above analysis will stand thus : The distillation of bromiferous mother-liquors with HgS 90'97 manganese and sulphuric acid is conducted in large cubic Fe,S8 1:37 stone vessels made in one piece, and belted with iron bands I'95 in case of a fracture. Their average capacity is 3 cubic Fe2O3 3:36 metres. At some distance from the bottom is a perforated 3:06 plate of the same kind of stone, upon which the manga nese is placed in fragments of the size of a nut. The 100*71 stone trough is covered with a heavy plate of the same These results may serve to explain, at least in some material, which is raised and lowered by means of a rope cases, the abnormal proportions of sulphur and mercury with a counterpoise playing over a pulley. In this cover in the published analyses of cinnabar, the iron having there is introduced a thick stoneware pipe for the introhitherto always been reported present as ferric oxide, and duction of steam ; and it is also provided with a man-hole, no other mode of combination suggested for the sulphur, which is almost always in excess. Thus in the analyses | während des Letzten Jahrzehends." * " Berichte über die Entwickelung der Chemischen Industrie given by Dana and Rammelsberg, neglecting other constituents 1 bath salts" (bade-salse). + In Germany such saline mixtures are used under the name of .. Sulphur (in residue .. 100'00 .. FeS2 SiO2 CHEMICAL News, 181 On Vegetable Fibre. an aperture for pouring in the bromiferous liquid and the In speaking of epidemics of typhoid fever the author dilute sulphuric acid, and an opening for the escape of the states" In the case of the Marylebone epidemic, in 1873, bromine vapours. the cause was traced to the milk from a certain farm far Few stones are suitable for the construction of these away in the country. The farmer had died of typhoid, vessels, and when the bromine manufacture was intro and his excreta had contaminated a certain well, with the duced at Stassfurt there was great difficulty in finding a water from which the milk-cans were washed." We suitable quality. Almost all the stones tried experi- really were of opinion that this alleged Marylebone epimentally after a time allowed the chloride of manganese demic had been consigned to the realms of mythology. to ooze through, and required to be coated with tar to There is scarcely a sound link in the chain of evidence overcome this defect. This, however, gave rise to a new which was produced on the occasion. The deaths from inconvenience, considerable quantities of bromine being typhoid in the district, at the time given, were below the lost by the conversion of the hydrocarbons of the tar into average. The farmer was certified as having died of a bromine compounds, and the bromine itself becoming con- disease of the heart. The water of the accused well was taminated. Dr. Frank estimates the loss for every new used for domestic purposes by several people in the village, coating of tar at about 50 kilos. of bromine. Latterly a none of whom were attacked with enteric fever. kind of stone has been found in the neighbourhood of A regular inspection of dairies, as Dr. Downės recomPorta Westphalica which does not require this costly mends, would be an exceedingly difficult thing to carry preparation and can be used at once. Still the high price out in practice, and would assuredly be avenged upon of these stone troughs has given rise to attempts to manu- consumers in the shape of a fearful rise in the price of facture bromine stills with large plates of slate, cramped milk and butter. together with iron bands and screws. A final decision Upon the whole we must say that this little work de. has not yet been obtained. serves a wide circulation, and is calculated to effect much (To be continued). good. a Vegetable Fibre, and its Preparation for Industrial Uses* NOTICES OF BOOKS. By Dr. Hugo Müller (of London). Brunswick: F. Vieweg. This valuable work is a reprint from the official report of How to Avoid Typhoid fever and Allied Diseases. By the Vienna Exhibition of 1873. The author sets out with ARTHUR H. Downes, M.B., M.D. London: Baillière, an account of cellulose, the formation of wood and cork, Tindall, and Co. textile vegetable tissue, the nature of the bleaching proThis pamphlet gives plain and useful directions how to cess, the distinctive characteristics of the different vege. prevent the introduction of sewage-gases into dwellings. table fibres, the quantitative determination of cellulose, The dangers of allowing water-closets to be supplied from and the hygroscopic nature of vegetable fibre. On the the same cistern which furnishes water for the culinary latter very important subject the author gives a table, from purposes of a household is clearly shown; so also are the which we learn that Belgian flax in its air-dried condition shortcomings of the ordinary drain-traps, and of sinks contains 5'70 per cent of water, cotton 6:66, and Manilla which lead direct into the sewer. The author urges that I hemp as much as 12.5. In air saturated with aqueous water-closets should always be built projecting from the vapour the amounts taken up are much greater. Thus house, and be provided with a kind of ante.chamber fitted cotton absorbs 20-99 per cent, and Manilla hemp 40. with a window on each side, so that the closet itself may for the purchaser of fibrous materials, but they are even These figures have not merely a commercial importance not be ventilated into the house. Such arrangements are certainly very desirable, but unfortunately they are beyond which when supposed to be dry may contain 6 per cent of more interesting as regards public health. Substances the reach of the many. In some towns the closets are placed in the interior of the houses, without any window water must certainly have a deleterious effect when worr. or any other direct communication with the open air. next to the skin. An astonishing number of coughs and But even this is not the worst. We once observed clouds rheumatic attacks, and in tropical climates of more acute of steam issuing from the closet in a certain hotel where diseases, are due to the linen and cotton under-clothing our evil star had led us to take up our quarters, and we still worn by so many. fear that there must have been some connection with the Müller very justly remarks that this end cannot, as a rule, On the recognition of the different vegetable fibres Dr. hot-water cistern in the kitchen. Dr. Downes denounces the vile practice of placing the be effected by chemical means, since the essential subfoundations of houses upon "made ground.”-i.e., accu stance present, cellulose, must when pure give always the mulations of putrescent rubbish. For this offence an same reaction. Only in exceptional cases certain raw appropriate legal enactment, with penalties heavy enough fibres give characteristic coloured reactions due to their to penetrate to the conscience of the wealthiest contractor, Zealand hemp, gives a red coloration with nitric acid, and less important constituents. Thus Phormium tenax, New is sorely needed. Not less do we require a stringent mea. sure prohibiting the passage of drains beneath the flooring jute and its allies a yellow colour with the sulphate of of houses, a mal-practice against which a large number of aniline; but when the fibres have been bleached these medical health-officers have formally protested. distinguishing reactions no longer appear. The microDr. Downes gives instances where the excreta of a scopic characteristics are more widely available. As has patient suffering from typhoid fever having been thrown been shown by the researches of Wiesner, almost all upon a dunghill, communicated the disease afterwards to vegetable fibres under the microscope display features by men employed in carting the heap away. It is exceed which they may be recognised. In addition to the geneingly probable, therefore, that fields irrigated with sewage rally constant length, breadth, and thickness of the memcontaining fever “germs” will communicate the disease brane of the cells which constitute any given fibre, there to persons employed in their cultivation. The author in are commonly detected other histological elements and deed remarks, in a foot-note,—"There is no evidence to crystalline mineral inter-deposits, which together form a show that even when a cow has been fed upon sewage basis for methodical examination. The application of manured grass the milk acquires any infectious property certain micro-chemical reagents—such as ammoniuret of per se." But there is evidence to show that the juices of copper, sulphuric acid and iodine, sulphate of aniline, &c. sewage-grass differ in their properties and behaviour from -is of great value. Still the detection of a manufactured those of natural grass, and that the milk of cows fed upon fibre remains a task which requires no little skill and sewage grass enters into putrefaction much more rapidly experience. than that of cows placed upon ordinary diet. * " Dic Piangenfaser und ihre Aufbereitung für die Technik." |