On Preserving brittle specimens in Botany and Zoology. &73 



Memorandum 3. 



The form of aquarium which, after upwards of five years' ex- 

 perience and observation on the natural habits of the various 

 animated tenants, I have now adopted, consists in a four-sided 

 vessel having the back gradually sloping upwards from the bot- 

 tom at an angle of 45 to 50 degrees, and the consequently ex- 

 tended top sloping slightly downwards and resting on the upper 

 part of the back. The bottom, therefore, becomes necessarily 

 narrow. The front for the purposes of observation, and the top 

 for the admission of light, are to be of glass ; the back, ends, 

 and bottom being constructed of slate; the whole fixed in a 

 stout framework. 



The advantages of this arrangement are : — 



First. That it allows of a most extended view of the whole 

 interior of the aquarium. 



Secondly. That it enables the occupants to resort to water of 

 any depth they may desire, or even to ascend the sloping back 

 and emerge from the water. 



Thirdly. It admits of a much larger surface of water being 

 exposed to the action of the light ; and 



Fourthly. The sloping top allows the water which condenses 

 on the glass, from the effect of radiation, to trickle off and return 

 to the aquarium without first resting on the zinc or iron frame- 

 work. 



I need hardly mention that the sloping back is to be covered 

 with light rock-work extending to a short distance above the 

 water line. 



XXXV. — On a Mode of giving permanent Flexibility to brittle 

 specimens in Botany and Zoology. By Prof. J. W. Bailey, U.S.* 



The excessive fragility, in the dry state, of many plants, and 

 particularly of those which secrete carbonate of lime, is well 

 known to botanists. There is no herbarium in existence in 

 which the specimens of Amphiroa, Jania, Corallina, Halimeda, 

 Liaqora, Char a, &c. are not in a more or less mutilated condition, 

 which becomes worse every time the plants are examined. In 

 studying a large collection of the stony Algce I was led to remark 

 their perfect flexibility while moist, which passed to great brit- 

 tleness when dry, and it occurred to me that if they could be 

 kept permanently moist they would remain permanently flexible. 

 I then remembered that General Totten, of the U.S. Engineers, 

 had mentioned to me, some years ago, his success in preventing 

 the cracking and peeling-off of the epidermis of various shells, 

 by impregnating them with chloride of calcium. I also remein- 

 * From Silliman's Journal lor Julv 1854. 



