52 
IOWA ACADEMY OP SCIENCE 
c density of substance or 1.070 ^ 
Sp. gr .=;5 r- >, — 7 = 1-072 sp. gr. 
density of HgO at same temp, or .998 
Clark gives the following specific gravities which have been worked out for 
other seeds. That we may compare them with the specific gravity of the apple 
seeds the following table is inserted: 
Specific Gravity 
Cruciferse 
Lettuce 
Solanaceaa 
Onion t. 
Carrot 
Grapes 
Buckwheat 
Naked Leguminous seeds 
Wheat 
Rye 
about 1.21 down 
1.10 
1.12 
1.18 
1.15 
1.16 
1.23 
1.30 to 1.36 according 
1.30 to 1.36 according 
......1.30 to 1.36 according 
to variety 
to variety 
to variety 
It will be seen from the preceding table that the Kings Apple had the high- 
est specific gravity of 1.188, followed by the Salome with 1.104, the Baldwin 
with 1.072, the Jonathon with .958, Iowa Blush with .935, Winesap with .9031, 
the Sweet Apple with .893, Northern Spy with .867, Greening with .665, Willow 
Twig with .449, the Wild Crabapple being the lowest with a specific gravity of 
.2488. 
BIBLIOGRAPHY. 
Clark, V. A. Seed Selection According to Specific Gravity. N. Y. Agri. Bxpt. Sta. 
25 :335-384. 
Cramer : Uber das Vorkommen und die Bnthstehung einger Pflanzenschleime. Pflan- 
zenphysioligische Untersuchungen von Carl Nageli und Carl Cramer, 1855, Heft. III. 
PI. 27. f. 3-5. 
De Leus, A. J. Dictonaire Universel de Matiere Medicale et des Therapeutiques gen- 
erates, Paris, 1830. 2 :558. 
Focke, W. O. in Engler and Prantl. Die naturlichen Pflanzenfamilien Rosacea, III 
Theil. 3 Abth. 22. 
Fluckiger & Hanbury. Pharmacograpliia. A history of the Principal Drugs of Vege- 
table Origin Met with in Great Britain and British India. London : Macmillan & 
Co. 1879. 269. 
Fluckiger & Tschirch. The Principles of Pharmacognosy. New York, Wm. Wood & 
Co. 1887. 166. 
Frank. Ueber die Anatomische Bedeutung und die Entstehung der vegetabilischen 
Schleime. Prigsheims Jahrbucher fur wissenschftliche Botanik, 1866. 5 :167. PI. 
15. f. 8, 9. 
Hanusek, T. F. Die Nahrungs-und Genussmittel aus dem Pflanzenreiche, Berlin, Kas- 
sel, 1884. 5:205 of Allgemeine Waarenkunde und Rohstoffe. 
Harz. Landwirthschaftliche Samenkunde. Berlin 1885. 
Henkel. Handb. Pharm. et. 365. 
Heraud. Nouvelle Diet. etc. 150. 
Herman Hager. Botanischer Unterricht in 160 Sectioneu fur angehende Pharmaceuten 
und studirende Mediciner. Berlin. 1885. 450. f. 657. (3rd ed.) 
Hill. Annals of Botany. 20 :395. 
Hofmeister, W. Ueber die zu Gallerte aufquellenden Zellen der Aussenflache von 
Samen und Perikarpien. Berichte der K. Sachs. Gesellsch der Wissenschaften, 
Sitzung Am. 20 Februar 1858:22, 30. PI. 1. f. 3. 
Karsten. Deutsch Flor. etc. 783. f. 449. 
Klenke Illustrirtes Lexikon der Verfalschungen der Nahrungsmittel und Getranke, etc. 
Leipzig, 1879. 518. (2nd ed.) 
Kratzmann. Die Lehre von Samen. 41. 
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