50 



chlorophyll with copper that Dr. Schunck had shown to remain 

 green when exposed to light. I at first made use of acetate of 

 copper dissolved to saturation in strong acetic acid, one part of the 

 solution being diluted with four of water. In this solution the 

 specimens were allowed to steep for a month or more, they were 

 tnen washed in clean water for a few minutes until clear of all 

 trace ot surface deposits of acetate of copper ; and they were then 

 transtprred to any preservative fluid desired. A short account of 

 tne process is given in a report on methods employed by me for 

 preservation of specimens submitted to a committee of the British 



5™ p J i" * ST f ted in that account ' the meth ° a ™ s found to 



Il^'f, ««£ in certain cases, the green being quite 

 permanent, and almost natural, except for a bluish tinge in it 



steened^n^T F the * pecimenB became brown while being 

 eemed wo st in tt^ ° a ? tate ° f copper ; and a8 «" brownta? 

 an nn T%£Z*T plants ' snch as 0ak < ^ contained much 

 formed wtthTf ^ * tlD ? that lt Was a compound of tannin 

 conTinued to u e t n . C0PPe I ' hat caused the discolouration. I 

 planS and varvi.^ tr^ . d M trying lt with differ cnt ^ups of 

 rapid and effSefb.n 6 $**** &S t0 eventration. The more 

 bv • deS than bv Hv^T ^ °\<»«*™ dyes and othe,> substances 

 killing the protop iIm g i„ P S t0plasm 8U ^ ested the ^vantage of 



It was found [hat ir th. he S l )ecimens «> rapidly as possible, 

 and of oCr aiJae tW P ;* eserv{ f °» of Spirog/ra in conjugation, 

 »se of stu Tentsdur wVi™ ^^ to keep in 8tock for th * 

 boilingthemSriaH?!^ J^ 8 ^ re3nlts were Stained by 

 it into the^^f 01 ^ 10 " * T^ te0t ^pper before putting 



compound FSES& 1 S£ r .^dehyde or spwf Thl 



rapidly, in the hot solution Wn 6 COpP . er Was formed ver ^ 

 Position had begun. SOlUtlon ' before any change due to decom- 



fojwe?^ ^ SiJftJ t0 la rger specimens naturally 



*»** the cr.ntinued s teenit T^ 6 " 1 ^ in th » se as compared 

 solution penetrated moreSon.b v' f* ^ lutIon - The hot 

 compound was formed 7n th Zt Vn d , W* and th * green 

 decomposition had tim tl b ^S b ! tlie hot acid bef, ' re 

 remain green when boiled in th!' « ? pUmta Were found to 

 even of those that had ah^b^^ <* acetate of copper 



heaM, C tw S0luti0n - Another verT^7 n ; Ahen mere1 ^ 8te ^ ed 

 beat b that it shortens very much thf r advanta ge of the use of 



of treatment depending nn tif e tlme required, the duration 



ror 17 " °? w ^ S^ P 3C«i^ °" the t; ^s oTe "h 

 tor submerged *»** .« _™« su mce for green seaweeds, and 



the cuticle is 



g stems of most 



li nr 9n 7" "" olumaia natural lv ,. Q ,, : °' 'hose with thick 



Atter they have hi 



ne Preservative fluids a* ;; cetate > th ey may be 



l8( or th ey may be dried, if 





