BIOLOGY. 803 



minutely described. They cause a dry, feverish, constricted feel- 

 ing iu the mouth, fauces, and throat, increasing until the fauces 

 become parclied and feverish, normal mucous discharges become 

 checked, and the feeling soon extends to the bronchial and pul- 

 m(Hiary surfaces, which also become dry, feverish, and constricted, 

 with a heavy, congested sensation and dull pain. These peculiar 

 symptoms generally last several hours after leaving the bog. 



Tlie author has made experiments relative to the production of 

 intermittent fever in localities entirely free from malarial influ- 

 ence, by carrying boxes iilled with surface earth from a malarious 

 drying prairie bog, covered Avith the palmellse, to these localities, 

 and exposing persons to their emanations. Attacks of intei-mit- 

 tent were the result. 



The investigations of Dr. Salisbury must be considered highly 

 imjiortant, as they seem to establish positively the fons et origo 

 of malarious fever. 



_Dr. E. Holden of Newark, N. J., late of the U. S. N., commu- 

 nicates a paper to the same journal, entitled, "An Inquiry into 

 the Causes of Certain Diseases on Ships of War," in which he ex- 

 presses his opinion that fever of an intermittent type is produced 

 by the growth of mould on board ship, under the action of hydro- 

 sulphuric acid of the bilge. 



ANESTHETIC AGENTS. 



New and Ready Mode of Producing Ancesihesia. — Dr. B. W. 

 Richardson has been for some years engaged in researches for the 

 production of local anaesthesia. Snow maintained that all narcotics 

 produce anaesthesia by the process of arresting oxidation. Dr. 

 Richardson has come to the conclusion that arrest of oxidation 

 means arrest of motion, and tliat anaesthesia, in truth, means the 

 temporary death of a part, i. e., inertia in the molecules of the 

 part. This led him to the conclusion that Dr. Arnott's plan of 

 using extreme cold was the first true step in the progress of discov- 

 ery ; and that if it could be made easier of application, and at the 

 same time could be combined with the use of a narcotic fluid, an 

 imiDortant advance in therapeutics would necessarily follow. 



By a simple apparatus, which divides an ether jet into a very 

 fine spray, he can produce local anaesthesia at any time, with a 

 cold six degrees below zero. He can distribute this spray into 

 any of the cavities of the body. 



When the ether spray thus produced is directed upon the outer 

 skin, the skin is rendered insensible within a minute ; but the 

 elfects do not end here. So soon as the skin is divided, the ether 

 begins to exert on the nervous filaments the double action of cold 

 and of ethel'ization ; so that the narcotism can be extended deeply 

 to any desired extent. Pure rectified ether used in this manner is 

 entirely negative ; it causes no irritation, and may be applied to 

 a deep wound, without any danger. Its chief appUcation is in 

 the production of superficial local anaesthesia; and it is admirably 

 adapted for a large class of minor operations, for which chloro- 

 form has been generally used. The ether must be pure. 



