MR. DAHLKE'S FILTER.

Westport Times, Volume II, Issue 169, 14 February 1868, Page 3

MR. DAHLKE'S FILTER.

The following account of a series of trials of a new description of filter, which would be very useful on the West Coast, is taken from the proceedings of the Royal Society of Victoria: — Mr. J. Cosmo Newbebt read the following report of experiments with Mr. J. Dahlke's filter : " At the last meeting of this society a paper was read by Dr. Neild, for Mr. J. Dahlke, describing a new filter which it, was stated, was peculiarly adapted for filtering water containing organic matter, or water which having passed through lead pipes or vessels,

contained salts of lead. Mr. Dahlke's statement, that it would remove acetate of lead and certain soluble salts from solution was so remarkable, and of such great importance, that I gladly undertook to try some -experiments witli the filter, and to report the results to you. lam much pleased to be able to corroborate all Mr. Dahlke's statements, and, indeed to go further. Upon receiving the filter, I poured into it a solution of sulphate of magnesia afrd common salt, and found Only traces in the water after it had passed through, so small, indeed, that they could only be detected by chemical ixeans. These salts were followed by strong acetic and then hydrochloric acids, the water being perfectly tasteless. I then added strong yellow sulpiride of ammonium, which passed through as pure water. Upon inverting the filter and pouring in hot water, the sulphide of ammonium was discharged undecomposed, showing that though it followed strong hydrochloric acid, it had not mixed with it. The washing was continued, and the hydroel loric acid was discharged-, followed in turn by the acetic acid. Similar experiments were made several times with the filter, with like results ; and it was not till a liquid which contained no water, and would not mix with water (i.e., benzole) was added, that the power of the filter was overcome. It is almost impossible to over-estimate the value of Mr. Dahlke's discovery as a household filter, and as a means of procuring fresh water at sea. I may state that some water taken from Hudson's Bay was perfectly pure and fresh when passed through it—containing very little more soluble salts than fan Yearn The value of the filter in many districts in this and the neighboring colonies will be very great, on account of the difficulty in getting water sufficiently pure even for cattle to drink. Mr. Bahlke is, I believe, prepared to erect filters large enough to purify from 10,000 to 20,000 gallons per day." Professor M'Cof remarked that he had been present at several of the experiments, and he could bear testimony to the wonderful character of Mr. Dahlke's filter which would be of inestimable value to persons living in the back parts of the colony, where good water could not be readily obtained. He should like to be informed, however, whether the filter possessed the property of dialysis, i.e., of separating crystalline bodies from all others.

Mr Newberry said that if the filter did not possess this property, it had something very much akin to it. He had not yet made all the experiments he hoped to make, but he believed the filter possessed the property of keeping back all crystalline bodies.

Professor Halford remarked that the subject was one of importance, looking at it from another point of view. There could be no doubt that disease and death had been produced by the introduction into the body of microscopic animal organisms contained in impure water, and it would be of great importance to ascertain whether this filter would separate such matter from water, and render it wholesome.

Mr Newberry now proceded to try some experiments with a small filter, which had been furnished by Mr Pahlke. He explained that the filter had been only made that morning, and as a week was required to bring the apparatus into its proper condition; he did not expect the results on this occasion to be so completely satisfactory as those described in the report. A strong solution of salt and water was first passed through the filter, and on being tasted by the members afterwards was pronounced to be only slightly brackish. Sulphate of ammonia, an intolerably offensive liquid, was next introduced with some water, and passed out as a pure, tasteless liquid* In reply to the president,

Mr. Dahi/ke said, that to make the filter available for household purposes, he proposed to attach it to the supply pipe, divided into two compartments, the first of which would arrest all the grosser impurities, and could be cleansed at stated intervals by the turning of a cock, while the second would form what might be called the real filter. Of course the 'filtering material must ultimately wear out, but he had had five years experience with an appa* ratus fixed at the General Post-office, London, and there had been no necessity to renew the filters. After some further conversation,

The President remarked that there was no doubt thot this filter not only did what Mr. Dahlke professed that it would do, but a great deal more. There seemed, in fact, to be nothing in the way of impurity that it would not remove : and there was no question that it would prove to he a most valuable filter.

THE CAUSES AND TREATMENT OF GRASS STAGGERS IN HORSES. During the late summer and autumn months horses are apt to suffer from indigestion, brought on by the eating of the tough hard sterna of ripened grasses, clover, of vetches, by the ripened seeds of rye-grass or by a meal of partially ripened corn. When green wheat or barley or otlier such succulent food is devoured, the symptoms of distress come on rapidly, the digestive canal is throughout distended with gas, the animal paws, rolls about, exhibits all the symptoms of an acute attack of flatulent colic, and occasionlly is quite, phrensied by the brain becoming involved through what is somewhat conveniently termed sympathy. Horses, when fed for a week or two on hard indigestible food, suffer from a more chronic variety of indigestion, generally known as grass or stomach staggers —very familiar to most agriculturists, usually confined to the heavier breeds of horses fed on bulky green food, and peculiar to the present season of the year. Instead of coming on suddenly and violently, like most of' the other digestive derangmeuts of horses, the symptoms in such cases of stomach staggers appear gradually and insidiously, the horse is dull and stupid, ! hangs its head but still continues to eat and drink fairly ;by and by, however, he allows portions of the partially masticated food to drop out of his mouth, he appears rather too full, his bowels are confined, he walks j with a stradling uncertain gait, and in bad cases reels about as if drunk.; These symptoms may continue for several days with more or less severity whilst they altogether escape the observation of careless attendants —special attention being perhaps directed to the animal only when some paroxysm of. colic causes him to roll and throw himself about. On examination he is then found to be somewhat distended the fseces are dry, hard and of small amount, the urine high coloured, the, gait unsteady : but the breathing is quite natural, there are no evidences of fever, and the pulse, instead of being quickened is slower than usual-, and occasionally becomes irregular _ and even intermittent. The danger in all such cases mainly lies in their gradual insidious approach, and their consequently remaining unnoticed until the bowels become overloaded with tough, imperfectly digested vegetable fibre. Dry, tough fibreus food, if continued to be eaten for several days after the bowels have become torpid and over distended, obviously increases the mischief, and rupture, inflammation or nervous prostration proves the immediate cause of death.

Such cases of indigestion are easily, managed, provided they are early and rationally attended to. The cause of the mischief, if still in operation, must be removed ; in other words, the indigestible food must be withheld. In its place a sloppy laxative diet must for several days be sustituted. Cold bran mashes, linseed tea, treacle and water ; with an occasional handfull of fresh young grass, or a very little hay, will form the appropriate dietary. By the tim« that the animal has got dull and stupid the bowels have become torpid and difficult to move, and ordinary physic, accordingly, will seldom then operate. The purgative must in such cases be given in solution, arid conjoined with an active stimulant. A good formula consists of five or six drachms of aloes rubbed down in a pint of hot water, and then mixed with a couple of glasses of whiskey, or with an ounce each of sulphuric ether and medicinal ammonia. If no effect is produced in fifteen or eighteen hours, the dose may be repeated, and twenty grains of calomel added to the drench. To expedite the movement of the bowels soap and water clysters should be given every hour, the belly should be hand-rubbed several times daily, and if there are colicky pains or tenderness it ought to be stopped with hot water and then rubbed over with mustard; paste. Ten minutes walking exercise, at intervals of two or three hours, will likewise help to hasten the action of the physic. Frequently repeated doßes of purgative medicine are apt to nauseate the horse ; and hence, when too full doses fail to operate, it is seldom advisable to give any more. It is safer to trust to dilutents, a mash die*, clysters* handrubbing, and stimulants repeated several times daily, A little yeast given in the food, or as a draught, is sometimes serviceable. Even where there is pain and spasm it is wrong, in these cases of stomach staggers, to give opiates, for, although they may help to overcome the spasms, they certainly act injuriously in increasing the torpidity of the bowels. Tor a week or two after an obstinate attack of stomach staggers, the bowels are apt to continue torpid, and heice it is very essential that the sloppy laxative diet be persarvorad with,