The next table gives the Fahrenheit equivalent for every tenth degree Centigrade from absolute zero to the boiling point of water. To find the corresponding F. for any degree C., multiply the given C. temperature by nine, divide by five, and add thirty-two. Conversely, to change F. to C. equivalent, subtract thirty-two, multiply by five, and divide by nine.
| Cent. | Fahr. |
|---|---|
| 100 | 212 |
| 90 | 194 |
| 80 | 176 |
| 70 | 158 |
| 60 | 140 |
| 50 | 122 |
| 40 | 104 |
| 30 | 86 |
| 20 | 68 |
| 10 | 50 |
| 0 | 32 |
| -10 | 14 |
| -20 | -4 |
| -30 | -22 |
| -40 | -40 |
| -50 | -58 |
| -100 | -148 |
| Absolute zero | |
| -273 | -459 |
The following articles comprise a simple equipment for a laboratory class of ten. The equipment for larger classes is proportionately less in price. The following articles may be obtained from any reliable dealer in laboratory supplies, such as the Bausch and Lomb Optical Company of Rochester, N.Y., or the Kny-Scheerer Company, 404, 410 West 27th Street, New York City:—
| 1 | balance, Harvard trip style, with weights on carrier. |
| 1 | bell jar, about 365 mm. high by 165 mm. in diameter. |
| 10 | wide mouth (salt mouth) bottles, with corks to fit. |
| 10 | 25 c.c. dropping bottles for iodine, etc. |
| 25 | 250 c.c. glass-stoppered bottles for stock solutions. |
| 100 | test tubes, assorted sizes, principally 6" × ¾". |
| 50 | test tubes on base (excellent for demonstrations). |
| 2 | graduated cylinders, one to 100 c.c., one to 500 c.c. |
| 1 | package filter paper 300 mm. in diameter. |
| 10 | flasks, Erlenmeyer form, 500 c.c. capacity. |
| 2 | glass funnels, one 50, one 150 mm. in diameter. |
| 30 | Petri dishes, 100 mm. in diameter, 10 mm. in depth. |
| 10 | feet glass tubing, soft, sizes 2, 3, 4, 5, 6, assorted. |
| 1 | aquarium jar, 10 liters capacity. |
| 2 | specimen jars, glass tops, of about 1 liter capacity. |
| 10 | hand magnifiers, vulcanite or tripod form. |
| 2 | compound demonstration microscopes or 1 more expensive compound microscope. |
| 300 | insect pins, Klaeger, 3 sizes assorted. |
| 10 | feet rubber tubing to fit glass tubing, size 3/8 inch. |
| 1 | chemical thermometer graduated to 100° C. |
| 15 | agate ware or tin trays about 350 mm. long by 100 wide. |
| 1 | gal. 95 per cent alcohol. (Do not use denatured alcohol.) |
| 1 | set gram weights, 1 mg. to 100 g. |
| 1 | razor, for cutting sections. |
| 1 | box rubber bands, assorted sizes. |
| 1 | support stand with rings. |
| 2 | books test paper, red and blue. |
| 10 | Syracuse watch glasses. |
| 1 | steam sterilizer (tin will do). |
| 1 | spool fine copper wire. |
| 1 | test tube rack. |
| 5 | test tube brushes. |
| 10 | pairs scissors. |
| 10 | pairs forceps. |
| 20 | needles in handles. |
| 10 | scalpels.[TN8] |
| 12 | mason jars, pints. |
| 12 | mason jars, quarts. |
| 1 | alcohol lamp. |
| 1 | gross slides. |
| 100 | cover slips No. 2. |
| 1 | mortar and pestle. |
| 2 | bulb pipettes. |
| 1 | liter formol. |
| 1 | oz. iodine cryst. |
| 1 | oz. potassium iodide. |
| 6 | oz. nitric acid. |
| 6 | oz. ammonium hydrate. |
| 6 | oz. benzole or xylol. |
| 6 | oz. chloroform. |
| ½ | lb. copper sulphate. |
| ½ | lb. sodium hydroxide. |
| ½ | lb. rochelle salts. |
| 6 | oz. glycerine. |
The materials for Pasteur's solution and[TN9] Sach's nutrient solution can best be obtained from a druggist at the time needed and in very small and accurately measured quantities.
The agar or gelatine cultures in Petri dishes may be obtained from the local Board of Health or from any good druggist. These cultures are not difficult to make, but take a number of hours' consecutive work, often difficult for the average teacher to obtain. Full directions how to prepare these cultures will be found in Hunter's Laboratory Problems in Civic Biology.
INDEX
(Illustrations are indicated by page numerals in bold-faced type.)