NOTES AND MEMOEANDA. 183 



to the west, had admitted to the crib the purer water from the deeper 

 portion of the lake. He based this theory mainly upon the fact that 

 while the hydrant water had never contained any of the stipitate 

 diatoms growing in abundance along the shore, the free imattached 

 forms were always present, together with several species whose origin 

 had not previously been determined, but which he had found in abun- 

 dance in several of the more northern streams. 



Health of Professor Kuxley. — Our readers will be glad to learn 

 that Professor Bence Jones, the medical adviser of the Professor, 

 asserts that the statement that the Professor has shown a tendency to 

 phthisical disease is quite unfounded in fact. Mr. Huxley has never 

 at any time exhibited any disposition to lung mischief. He is suffer- 

 ing from overwork only, and there is every reason to expect that he 

 will soon return to England in good health. He gave up his place at 

 the School Board in order to spare himself on his return. 



How to make Sections of Small Fragments of Soft Tissues. — The 

 following facts are stated by Dr. Woodward in the new number of 

 the ' Lens ' ; most of them are, however, familiar to English workers. 

 Where the fragment is too small to be conveniently held between the 

 finger and thumb of the left hand while the knife is guided by the 

 right, it may advantageously be imbedded in some suitable substance. 

 In the German laboratories a mixture of wax and oil is extensively 

 used for this purpose, and has been highly lauded. At the Army 

 Medical Museum we have long since learned to give the preference to 

 parafi&ne, as more readily handled, more cleanly, and yielding alto- 

 gether better results with less trouble. A sufficient quantity of paraf- 

 fine having been melted over a spirit-lamp in a small porcelain capsule, 

 or any suitable vessel, is poured into a mould made by folding a piece 

 of ordinary writing-paper into any convenient form, and the fragment 

 of tissue is held in the middle of the fluid with a pair of forceps 

 until the cooling paraflfine is hard enough to retain it in place. It is 

 then left to itself until the paraffine is quite cold, when the paper is 

 unfolded, and sections can readily be made by cutting through the 

 paraffine in any desired direction. The sections as made are dropped 

 into alcohol, in which the tissue is readily disengaged from the paraf- 

 fine by a pair of small forceps. 



Collins's Li^ht Corrector. — A very useful piece of apparatus was 

 exhibited by Mr. Collins (17, Great Portland Street) at the Quekett 

 soiree, consisting of a brass stage-plate with a groove in which rotates a 

 diaphragm of four apertures, one of them being open and the other 

 containing blue glasses of special tint, and one with a finely-ground 

 surface. These effectually correct the yellowness of all artificial illu- 

 mination, making the light soft and agreeable to the eyesight as well 

 as improving the definition. It is in fact an improvement on Eainey's 

 Light Modifier so as to obtain more varied effects, and does not require 

 any special fitting, as it can be used on any microscope. 



