THOMAS HR-108 SAFETY STOPPERS are of bloomless, black, resilient, hea t resisting rubber composit ion, wi th low sulfur con ten t and long life. S t ra igh t bore of the convent ional s topper has been replaced by a fusiform bore wi th bevelled en t rance . In te rna l d iameter a t center approximate ly twice t h a t of a sealing band a t either end. Advan tages a r e :

Safety—Glass tubes can be easily inserted and re­moved, "particularly by students, with greater safety than with straight bore. Insertion is facilitated by bevelled entrance of bore. Tube slides through only the two sealing bands.

Larger Tubes—Fusiform bore permits insertion of larger tubes than is possible with straight bore. For example, tubes 6 to 11 mm can be inserted in sizes 5 to 9 inclusive.

Superior Composition—The stock contains more than 70% of pure virgin gum, possesses great elas­ticity, is free from surface sulfur and contains less than 0.75% free sulfur; no reclaimed rubber is used.

Heat Resistant—Temperatures up to 110° C do not affect shape, size or structure.

Long Life—Tests indicate useful life approximately five times that of common stoppers.

8807. Safety Stoppers, T h o m a s HR-108, as above described, one hole (fusiform bore).

Size Approx. no. Carton Number per lb. Contains 00 . . . 1 7 0 . . 1 6 8 . .

0 . . . 1 1 1 . . . . . . 1 0 8 . . 1 . . . 9 7 . . . . . . 9 6 . . 2 . . . 7 4 . . 72. . 3 . . . 5 5 . . 60. . 4 . . . 4 4 . . 4 8 . .

. . . 3 7 . . . . . . 3 6 . . by2.... . . . 3 1 . . 36. . 6 . . . 2 7 . . . . . . 3 0 . . 6 J ^ . . . . . . 2 4 . . . . . . 3 0 . . 7 . . . 20. . . . . . 2 4 . . 8 . . . 16. . 18. . 9 . . . 13. . 18. .

Per Dozen .1.24. .1.27. .1.38. .1.48. .1.67. .1 .81. .2.02

. .2 .18. .2 .33.

. 2 . 4 9 .

. . 2 . 7 7 . .3.12. .3.64.

Per Carton .15.81 .10.36 .10.02 . 8.07 . 7.60 . 6.60 . 5.52 . 5.94 . 5.29 . 5.68 . 5.05 . 4.26 . 4.97

8808. Safety Stoppers, T h o m a s HR-108, as above described, but two hole.

Number 00

Approx. no. Carton

o... ι . . . 2 . . . 3 . . . 4 . . . 5. . . OV2-6. . . 6 ^ . 7. . .

per lb. . . 169. . .110. . . 95. . . 7 4 . . . 55. . . 4 6 . . . 3 8 . . . 3 3 . . . 2 8 . . . 25. . . 2 0 . . . 17. . . 14.

Contains . 1 6 8 . . . 1 0 8 . . . 9 6 . . . 72. . . 60. . . 4 8 . . . 3 6 . . . 36. . . 3 0 . . . 3 0 . . . 24. . . 18. . . 18. .

Per Dozen .1.34. .1.37. .1.48. .1.58. .1.79. .1.87. .2.04. .2.28. .2.42. .2.56. .2.83. .3.16 3.60.

Per Carton .17.04 .11.23 .10.78 . 8.65 . 8.15 . 6.79 . 5.58 . 6.23 . 5.52 . 5.81 . 5.15 . 4.31 . 4.92

5 % discount from carton prices in lots of 6 cartons; 10% discount from carton prices in lots of 12 cartons 20'/, discount from carton prices in lots of 2U cartons; 30% discount from carton prices in lots of lt8 cartons

one size, or assorted in carton units

For more detailed description, see pages 830-831 of our 7967 catalog; or Bulletin No. 134 sent upon request

9 2 A · ANALYTICAL CHEMISTRY

Thomas ARTHUR H. THOMAS COMPANY Scientific Apparatus and Reagents

V I N E S T R E E T AT 3 R D · P . O . BOX 7 7 9 · P H I L A D E L P H I A 5 , PA. , U . S . A .

Circle No. 80 on Readers' Service Card

to minimize glass breakage

Thomas S A F E T Y R U B B E R S T O P P E R S

WITH FUSIFORM BORE