Some persons eNposed to _action of vibrios remain unaffected. immunity is not due to killing of all microbes the stomach. Abel and Clausen (Centralb. f. Bact. Parasitenk., 11. 17, p. 77, '95).
We see that under certain meteorolog ical changes the epidemics show often quite marked exacerbations, and that, when the private and public sanitary conditions correspond to scientific re quirements, the disease is always less grave and more localized than under con trary circumstances.
The marked influence of winds and moisture is undeniable. Rosanotr (La Tribune 11CA., Jan. 2, '95).
Prevalence and mortality of Madras Presidency associated with two mon soons caused by rains, induced rise of subsoil-water and development of condi tions suitable for seasonable epidemic. W. G. King. (Brit. „lied. Jour., Feb. 2, '95).
Pettenkofer's view of the important part played by the level of the ground water in the cholera. epidemic in 1892 supported by comparative charts show ing the amonnt of rain-fall, the number of cholera ease6, and the level of the ground - water. As t he ground - water sank, cholera increased. 1'. llauser (La NIC4.1. Mod., June 9, 13, '94).
Symptoms. — The duration of the period. of incubation ranges in the ma jority of cases from 36 to 56 hours; it ! very rarely extends over several days. The clinical course of cholera may he divided into three periods: (1) premoni tory diarrhwa; (2) confirmed cholera; (3) reaction.
Premonitory diarrhcea begins more frequently at night, with or without colicky pains, under the form of liquid stools, at first frecaloid and then bilious and serous, with horborignaus, but with out tenesmus. Generally there is no fever, and no trouble of the appetite and of the general well-being; so that pa tients may not be obliged to go to bed. But, after it has lasted for a more or less long time (from a few hours to several days), the patient begins to feel a sense of weakness, pains in the limbs, dizzi ness, shiverings, and mental torpor. Pre monitory diarrhcea is always of choleraic nature, as the stools contain the specific germs and may disseminate the infection. It is not constant, being found only in one-third or two-thirds of the cases (ac cording to the different statistics); but it may be the sole manifestation of a very slight cholera.
Confirmed cholera is announced hy a change in the aspect of the stools, which, while becoming more frequent, consist of an aqueous fluid, without any fcaloid smell or appearance, in which many whitish, mucous flakes float, resembling grains of rice (whence their name of "rice-water" or "riziform" stools), formed hy the epithelial detritus and containing the cholera vihrios. In the meantime vomiting sets in, also of an aqueous material and accompanied by cramps in the stomach and prmcordial uneasiness. The thirst becomes burning and insatiable. The urine is scanty, often showing albumin and sugar (which disappear when recovery begins); but in many eases tbese are totally wanting, a complete anuria being tbe rule in grave forms. The tongue is whitish, large,
and damp. Palpation of the abdomen shows the anterior wall depressed and somewhat hardened. In proportion to the increase of the diarrlicea and vomit ing the patient grows weaker and weaker; the extremities become cold; the pulse small, weak, and accelerated; painful cramps develop in the calves; sinking of the features with sharpened, cold nose, sets in; and the circulation becomes sluggish, constituting together the "algid stage." This period may last from a few hours to one or two days, and may end in recovery with a progressive amendment of all the symptoms, constituting then the form to which the name "cholerine" was given by some authors; or it may end in death with symptoms of profound exhaustion, or finally pass, as we have said, into the algid stage.
This is announced by a lessened fre quency and abundance of the dejections, which sometimes cease altogether. In a few hours, however, the patient's general condition grows rapidly worse; the countenance is altered,—the cheeks become hollow, the eyes sunk deeper in the sockets, are encircled by a black ring; there are pains in the head, ear-tinglings, dizziness, and blurred vision; the voice becomes hoarse and is soon extinguished. A feeling of anxiety assails the patient, who suffers from the most excruciating vomiting, hiccough, and cramps in the calves. Cooling of the surface increases, all external parts being, as it were, frozen; but the patient feels an internal, very troublesome heat, explained by the fact that the temperature of the skin, mouth, etc., is much lowered, while that of internal organs is raised and even febrile. At the same time the skin takes a bluish tinge, with black marble-like veins coursing over the hands, feet, penis, and with increasing cyanotic dark hue of the nails. The pulse becomes weaker and smaller, until .it disappears, first from the radial arteries and then from the crurals and even the carotids, while the heart-beats gradually disap pear, the sounds becoming weaker until finally only the second sound is heard. To this great emaciation is added, the body growing thin and the skin wrin kled. Breathing is frequent and diffi cult; every secretion is dried up, with ihe exception of that of the sudoriferous glands, a cold and clammy sweat cover ing the cutaneous surface. At the end of this stage the patient becomes ex tremely apathetic and somnolent, loses consciousness, slowly turning his eyes toward a person speaking to him, and at times answering some words with great fatigue, but immediately falling again into stupor. A period of agitation, dur ing which the patient tries to rise and utter vague words sometimes precedes this stage of collapse, which generally— in more than three-fourths of all the cases—grows worse, and ends in death. The whole duration of the algid stage is from a few hours to two or three days.