Rheostat

“ Simple Rheostat. The No. 28 and No. 30 G-s wires stretched upon the board (Fig. 96) , make a convenient form of rheostat. The resistance per cm. being known from the results of Exp. 133 and 136, the resistance for any number of cm. is easily found. The 10-cm. divisions should be divided into centimeters. These spaces may be marked off from the rule (No. 88) .
[139]
Fig. ”

“ The A Battery Potentiometer.--This device is simply a resistance like the rheostat described in connection with the preceding vacuum tube receiving sets but it is wound to 200 or 300 ohms resistance as against 1-1/2 to 6 ohms of the rheostat. It is, however, used as well as the rheostat. With a vacuum tube detector, and especially with one having a gas-content, a potentiometer is very necessary as it is only by means of it that the potential of the plate of the detector can be accurately regulated. ”

“ Dr. Arcot was smiling amusedly at his son. “I can't very well control this except by standing directly in front of it, but I suppose you know what you're doing.”
“Oh, this is a laboratory model, and I haven't gotten the thing into shape really. Look at the conductors that lead to the coil; they certainly aren't carrying ten K.W.”
Dr. Arcot slowly rotated the rheostat. There was a faint hum from the coil; then it was gone. There seemed to be no other result. He rotated it a bit more; a slight draught sprang up within the room. ”

“ In Roux’s apparatus, made by Lequeux, the make and break is attained by the movement of one limb of a bimetallic thermostat, and in some forms a resistance coil and rheostat are placed in the circuit.
At the Pasteur Institute in Paris, and at other large laboratories in France, the bacteriological incubator is raised to the dimensions of a room. In the centre of this room is a large boiler heated by gas-burners, the fumes from which pass through a large flue to the outside. The flame of the burners is regulated by a bimetallic thermostat. The gas by-pass can be regulated by an attendant. ”

“ The bare constant error does not remain exactly the same at all times for any individual and is probably less regular in tactual time than in auditory or in optical time, according to the irregularity actually found and for reasons which will be assigned later.
3. The third group of experiments introduced the factor of variation in intensity of stimulation. By the introduction of a loop in the circuit, containing a rheostat, two strengths of current and consequently of stimulus intensity were obtained, either of which could be employed as desired. ”

“ All resistance for rheostats is to be placed on the back of the tablet. Contacts must project through board to front side. All moving parts must be on front of board.
33a. Tablet. Furnish and place where shown, a slate tablet not less than 3⁄4 in. thick, supported by a substantial angle bar frame, so placed that there will be a space of not less than 4 in. between the wall and back of resistance. Mount on the tablet one double-pole, 250-volt knife switch, with two 250-volt enclosed fuses and one starting rheostat, as specified hereinbefore. ”

“ But we have to explain the agency of another class of very different, and apparently opposite remedies. Alkalies are employed with benefit both in Rheumatism and in Gout; particularly in the former disease. Now I conceive these to act, in Rheumatism at least, simply on the Restorative principle; supposing lactic acid to exist in excess in Rheumatic blood. This by itself may have no more tendency to oxidize into carbonic acid, than so much vegetable acid would have. In ordinary cases a free vegetable acid passes out into the urine without undergoing any change in the system. ”

“ Folks with rheumatiz had ought to drink all the water they can swaller. They had ought to drink more'n they eat.”
“I dunno what you mean, Cephas.”
“It stands to reason. I've worked it all out in my mind. Rheumatiz comes on in wet weather, because there's too much water an' damp 'round. Now, if there's too much water outside, you can kind of even it up by takin' more water inside. The reason for any sickness is—the balance ain't right. The weight gets shifted, an' folks begin to topple, then they're sick. ”

“ From this idea of the rheumatism being not a primary disease, like the gout, but a transferred morbid action owing to the previous torpor of some other part of the system, we perceive why it attacks weak people with greater pertinacity than strong ones; resisting or recurring again and again after frequent evacuations, in a manner very different from primary inflammations; because the cause is not removed, which is at a distance from the seat of the inflammation. ”

“ Flour of sulphur dusted into the soles of the shoes and stockings is said to be a perfect preventive. The exciting causes of rheumatism are cold or wet applied to the body when in a state of heat, exposure to cold winds, remaining long in wet clothes, sleeping in a damp bed, or blood-poisoning. Acute attacks of rheumatism should be treated by painting the affected part with tincture of iodine.
Seasickness.—Experts claim that seasickness can be regulated by a system of breathing. One must sit still and time the breathing to the upward and downward motion of the boat. ”

“ Hay fever, bronchial asthma and neuritis are conditions in which it is recommended. The claim is made that
“Uricsol quickly controls Vasomotor Rhinitis and eliminates such conditions from the system.” “In fact, it will correct FAULTY METABOLISM.”
To a few practitioners of an older generation the pharmacologic basis of a remedy for rheumatism was sufficiently defined by saying that it increased the solubility of uric acid or affected it in some way. ”

“ Lactic acid is the most copious product thrown out in the disease called rheumatic fever, and, as many of the phenomena resulting from that disease take the same form and character as those producible by lactic acid, I infer from the best evidence attainable that this acid, the product of a fermentative change going on in the body during acute rheumatism, is the cause of the secondary structural affections which so frequently follow acute rheumatism. ”

“ If it be asked why Hydropathy has proved itself so effective a remedy in curing rheumatism, we would answer, on account of its great power in strengthening and invigorating the stomach and digestive organs, in the derangement of which, the cause of that disease is to be found. Rheumatism proceeds from a sluggish circulation in the extremities, consequent on a low vitality in the system, arising from a derangement of the digestive organs and viscera ”

“ Treatment of Chronic Rheumatism. The general alkaline baths recommended in the acute affection are also valuable in the chronic. The spirit vapor-bath, the Turkish, as well as the sulphur vapor-bath, are all worthy of a trial in this obstinate and painful disease. Alternatives are a very valuable [pg 429] class of agents in chronic rheumatism. The following mixture, in teaspoonful doses three times a day, in alternation with the Golden Medical Discovery, has proved very successful in this disease: acetate of potash, one ounce; fluid extract of black cohosh, one ounce ”

“ Rheotome, rē′ō-tōm, n. a means by which an electric current can be periodically interrupted. [Gr. rhein, to flow, temnein, to cut.]
Rheotrope, rē′ō-trōp, n. an instrument for periodically changing the direction of an electric current.—n. Rheot′rōpism, the effect of a current of water upon the direction of plant growth. [Gr. rhein, to flow, trepein, to turn.]
Rhesus, rē′sus, n. the boonder, one of the most widely distributed Indian monkeys, much venerated by the natives: (entom.) a genus of coleopterous insects.—adj. Rhē′sian. [Gr.] ”

“ It is, however, upon signs which are of a more general character that we ought chiefly to rely for diagnosis. The fact that the patient has previously experienced a genuine attack of [226] acute rheumatism, though of some value, is by no means to be taken as a conclusive argument that the present attack is of a rheumatic nature. The really important matter is, that whether the patient has or has not suffered acute rheumatism before the occurrence of the subacute or chronic form, the latter will always be attended by more or less of the specific constitutional disturbance of rheumatism. ”

“ Persons who are subject to frequent returns of the rheumatism, will often find their account in using medicines, whether they be immediately affected with the disease or not. The chronic rheumatism is similar to the gout in this respect, that the most proper time for using medicines to extirpate it, is when the patient is most free from the disorder. ”

“ There are many causes of rheumatism, but overeating is the chief and it is very doubtful if a case of rheumatism can develop without this main cause. Exposure is often given as the cause, but a healthy man with a clean body does not become rheumatic.
Rheumatism is due to internal filth. A filthy alimentary tract makes filthy blood. Some say that the poison in rheumatism is uric acid, and perhaps it is, but there are no uric acid deposits in the body of a prudent eater. The elimination in this disease is imperfect. ”

“ The acetate of potash taken in doses of five grains, well diluted with water, every three or four hours, is very valuable in acute rheumatism. Its alkaline qualities tend to neutralize the acid condition of the fluids of the system, and it also possesses diuretic properties which act upon the kidneys, removing the offending blood-poison from the system through these organs. If the joints are very painful, cloths wet with the Compound Extract of Smart-weed and applied to them, and covered with hot fomentations, very frequently relieve the suffering. ”

“ The occurrence of gout in connection with the excess of uric acid in the system is strongly suggestive of this, and the frequency of muscular rheumatism in pampered, overfed dogs with diseased livers and abnormal hepatic products, seems to give further support. Even in man, the subject of acute rheumatism, often leads a luxurious life and suffers from inactive or disordered liver, while in man and animals alike, a low grade of health and imperfect functional activity of important organs, are often precursors and accompaniments of acute rheumatism. ”

“ We come to the conclusion, then, that rheumatism is not a mere inflammatory pain of the sheaths of the muscles, but has its origin in some digestive irritation—exhibited by a certain kind and amount of fibrous inflammation, and this may be caused by the circulation of this acid blood, in its passage through the minute cappillaries of the joints and tendons, since nothing but the white and thin blood can pass through the circulation of the tendons and ligaments. ”

“ Without any apparent reason the poison of rheumatism habitually attacks one joint on one day, and another joint on another day, and with as little apparent reason it occasionally falls of a sudden upon the inhibitory heat-centre, and actually paralyzes it. In a few minutes intense fever is developed, and the bodily temperature rapidly approaches nearer and nearer that line on the other side of which is death. ”

“ Indeed rheumatism appears more prone to attack the serous membrane lining the heart cavities than that enveloping it externally. One reason for this is to be found in the great and incessantly recurring strain on the fibrous structure of the valves, and particularly in hard worked horses and hunting dogs in which the strain is often extreme. It has been argued that the increased blood pressure caused by digitalis is an appreciable cause. Its frequent connection with rheumatism is shown in the rheumatic lesions of joints and fibrous structures seen in carcasses dead of endocarditis. ”

“ They are, it is true, produced by different remote causes, but this constitutes no more difference in their nature, than is produced in a coal of fire, whether it be inflamed by a candle, or by a spark of electricity. The morbid actions which are induced by the usual causes of rheumatism affect, though less frequently, the lungs, the trachea, the head, the bowels, and even the heart, as well as the gout. ”

“ Mebbe you never had the rheumatiz. I’ve had it twenty year. I can’t get red of it, anyways. I’ve tried the [218] Century liniment—the one that has the man riding over snakes an’ things—and the arnicky, and ev’ry kind the drug-store keeps. I’ve wore salt in my shoes tell they turned white all over; and I kep’ a buckeye in my pocket tell it wore a hole and fell out. But I never get red o’ the rheumatiz.”
Mrs. Wincoop took two or three stitches in silence; then she said—“Patience, now, she can talk o’ having rheumatiz. She’s most bent in two with it when she has it—and that’s near all the time.” ”

“ In most if not all of these frightful cases of sudden accession of severe nervous symptoms in rheumatism the temperature will be found, on testing it, to be exceedingly high—108°, 109° or even 110° Fahrenheit. If the views advocated in this paper be correct, it is not the rheumatism, but the intense bodily heat, which causes the severe symptoms, and finally death. The joints lose their sensitiveness, not because the disease has left them, but because the heat so overpowers the brain that it has lost its power of perception: the patient's leg might be cut off without his feeling it. ”

“ If we wish to produce similar reactions outside of the organism, we generally employ a high temperature and substances which would destroy the organism itself. For instance, to prepare hippuric acid from benzoic acid and glycocol, in the laboratory, it is necessary to heat both for some time to 160°, while in the body it is only necessary to dissolve them in blood, and pass the solution through a kidney, when a combination is effected. ”