Emphysematous Anthrax. 225 



occurence of freshets, and the washing out of soil infection which 

 would otherwise remain buried. Also in advanced summer and 

 autumn when swamps, ponds, basins, deltas, river bottoms, etc., 

 are drying out and furnishing pasture. Pease records its great 

 prevalence in the rainy season in the swamp districts of the Pun- 

 jab and North Western provinces of India, and the same is largely 

 true of our Gulf coast states. 



Symptoms. Emphysematous anthrax develops suddenly, the 

 incubation in experimental cases, lasting only for a few hours, 

 (casual cases 1-3 days, Friedberger) and the whole course of the 

 disease does not usually exceed J^ to 3 days. The local swelling 

 may be the first observed symptom or there may be first febrile 

 disturbance followed by the local swelling. The swellings show 

 where the connective tissue is loose and abundant as on the 

 shoulder, quarter, arm, thigh, neck, face, or trunk, and practi- 

 cally never where the areolar tissue is very spare and dense as on 

 the end of the tail, or ear, or on the limb below knee or hock. 

 They sometimes form on the palate, base of the tongue, or phar- 

 ynx. The muscular system is especially liable to suffer, the loose- 

 ness of the texture and the presence of lactic acid making a par- 

 ticularly favorable field for the propagation of the microbe. The 

 comparative absence of muscle in the region below the metacar- 

 pus, the tail and ear is an important cause of immunity. 



The swelling is at first very small and tender, but it increases 

 rapidly, and in a few hours may extend to one, two, or three feet 

 in diameter. At first smooth, rounded, pitting on pressure and 

 destitute of crepitation on handling, it becomes softer 'and less 

 sensitive and when pressed or kneaded it gives a crepitant sen- 

 sation and sound, or it even appears to gurgle. When percussed 

 the resonance is drumlike. Finally, the skin may become cold, 

 insensible, and withered like a piece of parchment. When in- 

 cised the tissues are found to be gorged with blood, and of a 

 black or dark red color ; they break down under pressure into a 

 bloody pulp, and from the wound flows a bloody fluid which may 

 be red in the early stages, black in the advanced, and frothy in 

 the latest. Where the connective tissue is very loose and abun- 

 dant, the bloody extravasation is surrounded by an extensive 

 straw colored cedematous infiltration. The swelling is sometimes 

 single, but more frequently several appear and become confluent. 

 The lymph glands in the vicinity become greatly enlarged. 

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