Notes and Memoranda. 



391 



ffiS 



before the French Academy, one from M. Heiss, of Munsfcer, who says that his 

 sight enables him to see it nearly all the year, and not only in mornings of March 

 and evenings of September. He reminds M. Faye, to whom his communication is 

 addressed, that he has observed with the naked eye 2000 more stars than Arge- 

 lander includes in his Uranometria Nova. 



Arrangement eor Carrying Microscopic Objects.— The injury sustained 

 by mounted microscopic objects in being conveyed from place to place, is familiar to 

 all microscopists. The source of this injury arises chiefly from the loose manner in 

 which the glass slides fit into the containing box, and the consequent shaking they 

 receive in their transit from one place to 

 another. To remedy this evil a very suc- 

 cessful plan has been devised by Mr. A. H. 

 Church ; it is represented in the annexed 

 engraving. Attached to the interior of the 

 lid of the box, in which the slides are to be 

 kept, are a number of small pieces of wood 

 about; half an inch long and one-eighth of an 

 inch thick, fixed at regular intervals, corre- 

 sponding to the spaces between the grooves 

 in which the glasses rest. Inside the lid, 

 and resting on the rounded tops of these 

 little pieces of wood, a piece of silk-covered "elastic" is fastened, from end to 

 end, without stretching. If the pai*ts be properly adjusted, the slides will not 

 shake when the lid is closed, as each slide presses the India-rubber elastic between 

 two of the small studs on the lid, and in this manner is held steadily. The great 

 recommendation of the contrivance is the fact that a single slide is as securely 

 held as when the box is filled. Microscopists will readily appreciate the advan- 

 tage of an arrangement which enables them to carry any number of objects with- 

 out producing a continual rattling, and which precludes any liability to displace- 

 ment or injury from concussion.. 



Potash prom the Animal Kingdom. — The supply of potash has hitherto 

 been solely derived from the vegetable kingdom. Recently, however, M. Mau- 

 mene', a French chemist, has obtained it in considerable amount from animals. 

 When sheep's wool is submitted to the action of cold soft water, a kind of greasy 

 soap dissolves ; this is a combination of certain fatty and oily acids with the alkali 

 potash. It is found that by heating this soap to redness, a verypm*e carbonate of 

 potash is obtained ; this process is so productive that it is worked as a commercial 

 speculation at Rheims, and samples of the various potash salts were shown in the 

 International Exhibition. 



New Applications op Aluminium and its Allots. — Messrs. Bell 

 Brothers, of Newcastle, have recently produced a new modification which they 

 term " whitened aluminium," in which the unpleasant zinc-like hue of the metal 

 is obviated. They have also formed keys of aluminium, alloyed with two per cent. 

 of nickel to increase its hardness. Aluminium bronze is now made of three 

 qualities, the first containing ten, the second seven and a-half, and the third five 

 per cent, of aluminium, the residue being copper. These varieties of the bronze 

 are scarcely to be distinguished in appearance from gold ; their specific gravity, 

 however, being rather less than that of copper (8 '95), differs remarkably from that 

 of the precious metal, the specific gravity of which, when pure, is as high as 19"5. 

 From aluminium wire and foil the lighter weights used for chemical purposes, 

 may be advantageously made, since occupying something like seven times the 

 space of those of platinum, they are more easily adjusted and handled, and less 

 likely to be lost. The finest aluminium wire, from its insignificant weight, advan- 

 tageously serves to suspend from the beam of the balance, objects the specific 

 gravity of which is being ascertained. MM. Collet, of Paris, have constructed a 

 chemical balance in which, not the beam only, but every part, clown to the 

 milled head by which the beam is released, is made of aluminium. 



The Reaction of Iodine. — At the September meeting of the Societe Sel- 

 mtiques des Sciences Naturelles, M. Schonbein pointed out that the proto-chloride 



