°^- llccvnt Microscopic Literature. 



varnish made by dissolving copal in essential oil of lavender. 

 A drop of this varnish is placed on the slide, the object laid on 

 it, covered with thin glass, and set aside in a warm place for 

 a, few days. Another varnish, which he affirms to give ex- 

 cellent results, is composed of- — 



Canada balsam 00 grammes. 



rs of mastic, powdered .10 „ 

 Chloroform in sufficient quantity. 



1 he chapters on preparing objects are very good, bnt most 

 of the information is the same as that given in Mr. Davies's 

 work. M. Chevallier, as the latest contribution to this subject, 

 • the following- process, modified from that prepared by 

 Mr. Leader of Philadelphia. He says, " I have lately tried a 

 new compound which has given very good results, with Navi- 

 culse and other delicate objects. Here is the formula-. — In 

 30 grammes of chloroform dissolve 1 gramme of caoutchouc. 

 When the solution is effected, add tears of mastic until a 

 syrupy or demi-syrupy consistence is obtained." The object 

 is put in a drop of this solution on a slide, gently pressed and 

 allowed a day to dry, after which the edges of the covering 

 i 'rushed. It is said to be perfectly transparent and 

 unalterable. 



Before leaving i ■ ict of mounting, we must allude to 



Freestone's new mounting-table, described by Mr. Grodi 

 in the ( (ioroecopic Science for April, 1864, 



p. 45. The object of Mr. Freestone's invention is to dry and 

 harden slide:; rapidly, without injury to the obj< 



"It consists of of brass 12 inches b one- 



Lth of an inch thi< on this, two piece balofthe 



1 12 inches by 1)8*1 



one inch wide in the centre of the plateg the whole 



I: on tubular legs ght inches high" 



poss i bis table, which id by a spirit 



lamp mi b, and from the form of (he table the] 



object does not touch the bn , but 



d by conduction, radiation, and by currents of bot air. 



Mr. Goddard Btates thai deli< wreeds,snch as Plocammm 



■ ad Cladophera, can be mounted in balsam by the aid of this 



I beir colour. 



MirrV work many allu 



pparatus nol well known in this eountryj but 



variable objective" invented by his father we bave not 



1 .-in opportunity of and, from thi iption, it 



lit be very bandy. " It is composed of two brass lubes 



one in the other j and .-it the extremity of each tube is 



achromatic Lens of long locus. . . Uy mean 



