G. GENERAL NATURAL HISTORY AND ZOOLOGY. 271 



liquid or immersed in it, the preparations always remaining 

 soft and flexible if brought into tepid water. The compound 

 has no action whatever upon the injecting or dissecting appa- 

 ratus. 13 C, August 1, 1873, 1030. 



PRESERYATION OP FLESHY FUNGI. 



The preparation and preservation of the fleshy fungi have 

 long been difficult problems to the botanist, various methods 

 being adopted toward these ends with more or less success. 

 They will keep very well, of course, in alcohol ; but this is a 

 troublesome and expensive method, and only suited to large 

 museums. In consequence of their juiciness, and possibly of 

 the amount of nitrogen which they contain, they are very 

 subject to decomposition, and are attacked with great readi- 

 ness by insects. The usual method of preparing them is to 

 subject them to poisonous metallic solutions, but even this 

 does not appear to be sufficient. 



A recently devised mode of treatment, which promises 

 more success than its predecessors, consists in coating them 

 with a thin layer of collodion, thus investing them with an 

 exosmotic membrane. This allows the moisture to exhale 

 uniformly, and the plant to dry gradually, the shape, color, 

 and texture being but little aff*ected. The destructive agency 

 of the oxygen of the air is also excluded, and most insects 

 are unable to penetrate the collodion skin, or to introduce 

 their eggs or larvae beneath it. 1 A^ xxiv., 383. 



EXCRETION OP CARBONIC ACID FROM THE SKIN. 



Careful observations have been made by Dr. Aubert in ref- 

 erence to the amount of carbonic acid excreted by the skin 

 in man. For this purpose the subject was placed in a close 

 box accurately adapted to the neck, and having tubes con- 

 nected with it for the entrance and exit of the air, the tubes 

 being, of course, again connected with apparatus for the an- 

 alysis of the air, thus containing the products of the cutane- 

 ous respiration. The general result arrived at was that, in 

 the course of twenty-four hours, the maximum amount of car- 

 bonic acid exhaled was about 97 grains, and the minimum 

 about 35^, thus making a mean of 59.7 grains of carbonic 

 acid as eliminated from the whole surface of the body below 

 the neck. This, of course, is independent of the quantity ex- 



