SCIENTIFIC.

Otago Witness, Issue 1764, 12 September 1885, Page 28

SCIENTIFIC.

— When men first begin to work in very hot mines they lose their strength almost invariably and the slightest exertion is burdensome. They feel no desire to eat, and the stomach commonly rejects what food is taken. Ordinarily, also, the decrease in their weight is very considerable. This condition of body does not last more than three or fottr days usually. Then the men regain their vigour, and flesh rapidly, their appetite returns and their health does not visibly suffer. In many instances the effect of heat is clearly beneficial. By the exercise of Care in avoiding sudden chills rheumatic affections are eradicated: all impurities of the blood arc rapidly purged from the system, boils, pimples, ann other eruptions soon disappear, the flesh becomes plump and firm, the glands secrete oil rapidly, the' skin grows smooth and slippery to the touch and the complexion is clear if somewhat sallow. This is the record of the U. T. census agents, who investigated this subject in 1880 on the Comstock, where there is an abundant field for examination and comparison. The ultimate effect of this extreme heat on the miner's constitution is not so easily noted. The mine levels on the Comstock differ so materially in temperature, and the assigned station of a miner is so frequently changed, that it is impossible to obtain complete and comparative data. That prolonged labour in a hot, impure atmosphere will assuredly shorten life appears indisputable, but whether the system is permanently or materially injured by intermittent work under these conditions is more questionable. The power of recuperation appears extraordinary, and unless the strain is intense and frequent no lasting injury may be inflicted. The limits of permissible strains will, of course, vary with the relative power of endurance. In the recent monograph of the U. S. Geological Survey, by Eliot Lord, on " Comstock Mining and Miners" it is stated on the authority .of the testimony procured by the census agents that the action of all the bodily organs of the Comstock miners appears to be stimulated by the heat with the exception of the stomach alone 4 The food of the ordinary labourer is unpalatable to the miner in the hot levels, and coarse illcooked provisions wouldnot be accepted or digested readily. The men crave fruits and highly-sea-soned dishes, pickles, pigs' feet, hams, almost every food with apureacid orsaltflavour. Theyclemand and obtain the best supplies possible to gratify the natural craving aud squearaishness of taste. The delicate condition, of their digestive powers is as undoubtedly due to the quantity of ice water "which they drink, as to the heat which they undergo. Yet they must have cool drinks at frequent intervals, and feverish men cannot be expected to gauge carefully the quantity or the coldness of the water which they heed. If the temperature of the water-tauks was regulated by the mine superintendents their employes would be less subject to dyspepsia. — A New York interviewer recently paid a visit to the w,ork-shop of Mr Edison, and among other things gives the following :— Perhaps the most intsresting thing ho had to say was respecting his exploration for a " new force." At present he calls it simply xy z. He does not pretend to know what it is. He says that there are many phenomena which are not explained by any force yet recognised, and it is these which lie is going to investigate. Vibrations of matter at the rate of 30,000 a second produce the highest sound we can hear. Between these and the vibrations which, at the rate of millions per second, cause the sensation of heat, "there is a large gap ;' and between these and the vibrations which give the sensation of colour there is another gap. These 'gaps, Edison believes, are filled by vibrations as yet unmeasured, which constitute the new, or unnamed force he is in search of.

— The Scientific American gives several illustrations of tlie fact that in almost every line of business there are men who excel, because Cicero's declaration that " a poet is born, not made," applies to others than poets. A man •whose business in a certain tool shop was to temper springs, worked 22,000 consecutively, and of the whole number only six failed to pass the test; but 'during his temporary illness more than half the .springs handled by his assistant, who had been under instructiou a year, failed. In a large manufactory of sword blades one man does all the tempering, being called in from other employment at intervals, because, although he has always been willing to instruct others, he has never had a pupil vdio could equal him in the work.' There is a largo scythe manufactory in a New England town, making 14,000 dozen scythes a year, and the president of the company has for years hardened and tempered every scythe that leaves the works, because no • other man in the works can do it so well.

. — Professor Tyndall thus endeavours to explain the immunity obtained against a second attack of a contagious disease : — " One of the most extraordinary and unaccountable experiences in medicine was the immunity secured by a single attack of a communicable disease against future attacks of the of the same malady. Smallpox, typhoid, or scarlatina, for example, was found as a general rule to occur only once in a lifetime of the individual, the successful passage through the disorder apx^arently rendering the body invulnerable. Reasoning from analogy, I have ventured to express the opinion that the rarity of second attacks of communicable disease was due to the removal from the system, by the first parasite crop, of some ingredient necessary to the growth and propagation of the parasite." — A casting has been made of the crown glass for the great Lick telescope, which, it is thought, will be a success, after quite a number of failures. Such is the report brought by Mr Chas. Plum, one of the trustees of the Lick estate, who has jnst returned from Europe. It is said the failure of the previous castings has been on account of a change in the management of the jlassworks, the father having given up the manigement to the son, who was comparatively inssperienced. The father has recently gone nek, and the result has been the restoration of heir works to the former standard of excellence, ad now we have the report that success; has .ttended the last casting, which is being polished 0 facilitate a more thorough examination of its haracter. It is expected that it would soon be eady to ship to Clark's at Boston, who will give ; its configuration, and they as well as the ■ustees feel quite sanguine that there will" be o further delays. The object glass will be 36 iches in diameter, and costs 50,000d01.

A Fact Worth Knowing.— Are you suffering nth Consumption, Coughs, Severe. Co^ds, settled on reast, Pneumonia, or any Disease of the Throat kd Lungs ? If so, go to your Druggist and get a Ittle of Boschee's German Syrup. The people

s going wild over its success, and Druggists all er our country arc writing us of its wonderful res among our customers. It has Vy far the •gest sale of any remedy, simply because it is of so icli value in all affections of this kind. Chronic ses quickly yield to it. Druggists recommend it, i. physicians prescribe 16. If you wish to try its >erior virtue, get a Sample Bottle for 6d. Large 5 bottle, 3b 6d. Three dosea '-vill relieve any case, rifc.— [Advt.l