66 



NAT0KAL SCIENCE NEWS. 



caught some practical ideas when 

 I first began, and thereby saved 

 me a vast amount of annoyance 

 and failures. I have made a trial 

 of 14 brands of photo, paper, and 

 unhesitatingly recommend that 

 made by the Ilotype Co., New 

 Brighton, Staten Island, N. Y. 

 For sale in every state in the Un- 

 ion. Ilo requires but one bath and 

 not one-third the amount of gold 

 that Albumen paper requires to 

 tone. It is universally acknowl- 

 edged, that a combined toning and 

 fixing solution gives just as beau- 

 tiful and permanent results, and 

 perhaps more so than separate 

 baths. 



Kosmos is another good paper. 



It does not sink to the bottom 

 like gelatine paper, but curls slight- 

 ly at the ends, just enough to keep 

 the prints separate, and making 

 easy work of washing, etc. 



After they have been toned and 

 thoroughly washed take them out 

 one at a time and lay them face down 

 on a paper, squeeze the Avater well 

 out of them, and mount while still 

 moist with thick starch paste. 



All of the new papers look quite 

 well before burnishing but a bur- 

 nisher gives a remarkably gloss en- 

 tirely unlike albumen. 



The platinotype process is very 

 largely used at present. Prints 

 similar to blue paper, but giving 

 black and sepa tones, and most 

 artistic effects. 



A. S. McKeen. 



Aquaria. 



An aquarium is not only an or- 

 nament, but is instructive and in- 

 teresting. It is particularly adapt- 

 ed for the sitting-room, library 

 and dining-room, and many times 

 has been introduced into the sick- 

 room, giving pleasure and enjoy- 

 ment also to children who delight 

 in watching the motion of the fish 

 and growth of the plants. 



The care of gold-fish is very 

 simple; they require but little food, 

 a few sheets of which will last a 

 long time. Care, of course, 

 should be taken not to put more 

 food into an aquarium than the 

 fish will consume within a reason- 

 able length of time. Feed a little 

 two or three times a week;this is all 

 that is necessary, according to the 

 number of fish in the aquarium, 

 which should never be over- 

 crowded with fish or plants. % Al- 

 low two gallons of water for three 

 gold fish of the average length, 

 three inches, ( of course the larger 

 .the fish, the more water they re- 



quire). Small size fish are recom- 

 mended. Fish should never be 

 handled except with a net. 



In regard to changing the water, 

 this depends entirely on circum- 

 stances; in a cool room, where the 

 air is pure, three fish will live in 

 two gallons of water for two or 

 three months, perhaps longer, 

 without changing; in a warm room 

 they will require fresh water often- 

 er. (I am now speaking of globes.) 

 Care should be taken in changing 

 the water not to bruise the fish. 

 Pour off the water carefully, and 

 pour in slowly the fresh water 

 which should be as cold as pos- 

 sible. If you keep the aquarium 

 in a cool place, exposed to the sun 

 a portion of the day, and stocked 

 with the proper quantity of plants, 

 the water need not be changed; 

 they have been kept for years 

 without removing the water. A 

 four-gallon aquarium will stand 

 for months without changing the 

 water, larger ones in proportion. 

 Simply add a little water each day, 

 as it evaporates, and keep the 

 aquarium close to a window, so 

 the average temperature will not 

 be more than sixty-five degrees; 

 the colder the better. Pebbles in 

 the bottom of an aquarium, also a 

 grotto or imitation stone arch, add 

 greatly to its beauty. These give 

 it the appearance of a miniature 

 lake; and with plants, etc., can be 

 arranged very artistically by one 

 who takes an interest and pleasure 

 in doing so. — From a Circular by J. 

 W. Fiske, New York 



General Directions for Micros- 

 copic Work. 



Bv E. S. Bastin. 



Prof. Botany, Phila. College of Phar- 

 macy. [From College Botany, 

 pp. 218-9.] 



1. Acquaint yourself thorough- 

 ly with the mechanism of the mi- 

 croscope you are to use. 



2. Observe great care in the 

 removing and putting on of ob- 

 jectives, so as not to drop them, 

 for they are delicately constructed 

 and liable to injury. The eye- 

 pieces and eye-piece micrometer 

 should also be handled with care. 



3. Observe care in focusing, 

 particularly when high powers are 

 used, so as not to run the objective 

 down against the slide and en- 

 danger either the cover-glass or 

 the objective itself. Be sure also 



that you focus the microscope a* 

 curately, otherwise the structure 

 of the object will not be distinctly 



seen. 



4. Give due attention to the a< 

 justment of the reflecting mirroi 

 so as to secure the most favorab 

 illumination of the object. Mu 

 of your success in seeing fine de 

 tails of structure will depend upq 

 the care exercised in this respec 



5.. Bear in mind that many 

 the reagents used are corrosi 

 and hence should not be broug 

 into contact with ,the microscop 

 All the acids and iodine reagen 

 will act upon brass work, pota, 

 sium hydrate will corrode glas 

 and alcohol will remove the la 

 quering from the stand. 



6. t All objects examined i 

 liquids should be covered, n 

 only to obviate the danger of in- 

 juring the objective, but to avoid 

 the inevitable distortion of the 

 image which a curved or uneven 

 liquid surface produces. 



7. Let cleanliness and care 

 characterize all your work in the 

 microscopical laboratory. Keep 

 all your apparatus, slides, cover- 

 glasses, etc., scrupulously clean. 

 Do not touch the glasses of the 

 objectives or eye-pieces with your 

 fingers, for that would be to soil 

 them and impair their optical per- 

 formance. Whenever they need 

 cleaning breathe upon the glasses 

 and wipe them either with a piece 

 of perfectly clean and soft linen 

 cloth, or with a piece of the thin, 

 soft paper that is sold at dental 

 supply stores under the name of 

 Japanese filter paper. A conven 

 ient way is to keep always at han 

 in a place secure from dust, quan 

 tity of this paper cut into suitabl 

 sizes. It is useful, also, for clean 

 ing cover-glasses, slides, etc. H 

 a fresh piece is used each time foi 

 cleaning an objective, there wilLbl 

 little danger of marring the polish 

 of the front lens. 



Keep the bottles containing 

 reagents, staining fluids, etc 

 stoppered, when not in use, so as 

 to exclude dust and prevent evap 

 oration; and take especial care in 

 using them not to introduce im 

 purities into them. 



8. In cutting sections the razor 

 or section knife chould always be 

 very sharp, and for most purposes 

 sections should L e cut quite thin 

 Steadiness in cutting is secured byj 

 resting the wrists against the body. 

 The knife should be given a 

 oblique or sliding motion whe: 

 drawn through the object. Quit' 

 hard tissues may be successfully 

 cut if the sections are cut quite 



