At the beginning of an epidemic, the average mortality from cholera is 50 to CO per cent. and even higher, while at the end, slight forms generally prevail ing, it g-rows progressively less. The largest proportion of deaths occurs in children and old people, the ished, enfeebled, paupers, drunkards, and those affected with debilitating. diseases, especially dysentery, cancer, consumption, insanity, etc.
AVliatever may be the gravity of the symptoms during the algid stage, even if there be intense cyanosis, if the normal or contracted pupils remain mobile,— that is to say, if they dilate when the eyelids are closed and return to their primitive diameter as soon as the lids are opened,—a favorable prognosis may be given. Coste (Revue de Med., No. 12, '90).
The prognosis of Asiatic cholera in young children is exceedingly bad. Of 4129 infants, aged 1 year and under, SO per cent. died; of 1701 children, from I to 5 years, 75 per cent. died; of 1731 children, from 5 to 15 years, 45 per cent. Floppe (Deutsche med. AVoch., Nov. 9, '93).
There is a urinary crisis in patients who recover, characterized by the dis charge of abundant urine of low specific gravity, rich in urates, but poor in chlo rides. As convalescence becomes more marked, the proportion of urea dimin ishes, that of the chlorides increases, the specific gra.vity grows greater, and the quantity- of urine returns to normal. Carrieu (La Med. Mod., Dec. 30, '93).
Prophylaxis.—Prophylactic measures are of the utmost importance. The im portation and propagation of cholera must be thwarted and healthy persons must be protected against contagion. The measures necessary may be summed up as follows: A careful examination of persons coming from infected places; isolation of those fouiad ill or simply suspected and of their nurses; thorough disinfection of clothes. linen, premises, dejections, rooms, drains, etc. For in dividual prevention it is necessary to drink only boiled water, to avoid every dietetic error, excess, mental or bodily strain, cold; and, while no radical change ought to be made in the ordinary ali mentation, the food must be of good quality and vegetable products should always be cooked.
Haffkine's prophylactic method, based on the inoculation of serum of immu nized animals, has been tried with satis factory results in India; but the dura tion of the protection afforded by the inoculation, and for some authors the efficiency of the protection itself, is still a matter of doubt.
An experimental inquiry of the bear ing on immunity of intracellular and metabolic bacterial poisons: As far as the cholera spirillum is concerned, (1) any one mocle of immunization will pro tect an animal against an infection by any other form of inoculation used; (2) the serum of an animal immunized by any one method also protects guinea pigs against an infection by any other forms of inoculation; (3) the distinction between an "intracellular" and a "metab olic" poison in their relation to artificial immunity must not be made too narrow. Kanthack and Westbrook (Brit. Aled. Jour., Sept. 9, '93).
The milk from an immunized goat has the property of conferring immunity to cholera, but not when introduced into the system by way of the stomach. It confers immunity at once, but is of no avail if given shortly after the injection of the cholera germs. Ketscher (Archly f. exper. Path. u. Pharm., .Nov.. '93).
Conclusion a‘
Endeavor to reconcile the varions di vergent views which have resulted front the studies of different observers: There are in the cholera vibrios distinctly-poi sonous substances, which are insoluble in the ordinary culture-media, but which are set free after the death of the bacilli in the bodies of guinea-pigs used for ex periments, and which then act as paral yzants to the centres governing the cir culation and the temperature. Conclu sion that, although the possibility of a. successful protective inoculation against human cholera cannot be denied, the existence of such a possibility has not yet been proved experimentally. R. Pfeiffer (Zeit. f. Hygiene u. Infectionskr., Mar. 2, '94).