# Observations of the Comparative, Intensive or Specific Gravities of Various Bodies. Made by Mr. J. C.

**Author(s):** J. C.  
**Year:** 1693  
**Journal:** Philosophical Transactions (1683-1775)  
**Volume:** 17  
**Pages:** 3 pages  
**Identifier:** jstor-101963  
**JSTOR URL:** <https://www.jstor.org/stable/101963>  

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I. Observations of the Comparative, Intensive or Specific Gravities of various Bodies. Made by Mr. J. C.

| Substance                                      | Gravity |
|------------------------------------------------|---------|
| Pump-water                                     | 1000    |
| Cork                                           | 237     |
| Sassafras Wood                                 | 482     |
| Juniper Wood (dry.)                            | 556     |
| Plum-tree (dry.)                               | 663     |
| Mastic                                         | 849     |
| Santalum Citrinum                              | 809     |
| Santalum album                                 | 1041    |
| Santalum rubrum                                | 1128    |
| Ebony                                          | 1177    |
| Lignum Rhodium                                 | 1125    |
| Lignum Asphaltium                              | 1179    |
| Aloes                                          | 1177    |
| Succinum pellucidum                            | 1065    |
| Succinum pingue                                | 1087    |
| Jet                                            | 1238    |
| The top part of a Rhinoceros-horn              | 1242    |
| The top part of an Ox-horn                     | 1840    |
| The (Blade) bone of an Ox.                     | 1656    |
| An human Calculus                              | 1240    |
| Another Calculus humanus                       | 1433    |
| Another Calculus                               | 1664    |
| Brimstone, such as commonly sold               | 1811    |
| Borax                                          | 1720    |
| A spotted factitious Marble                    | 1822    |
| A Gally-Pot                                    | 1928    |
| Oyster shell                                   | 2092    |
| Murex-shell                                    | 2590    |
| Lapis manati                                   | 2270    |
| Selenitis                                      | 2322    |
| Wood petrefied in Lough-Neagh                  | 2341    |
| Onyx stone                                     | 2510    |
| Turcois-stone                                  | 2508    |
| English Agat                                   | 2512    |
| Grammatias lapis                               | 2515    |
| A Cornelian                                    | 2568    |
| Corallachates                                  | 2605    |
| Talc                                           | 2657    |
| Coral                                          | 2689    |
| Hyacinth (spurious.)                           | 2631    |
| Jasper (spurious.)                             | 2666    |
| A pellucid Pibble                              | 2641    |
| Rock Crystal                                   | 2659    |
| Crystallum Disdiaclasticum                     | 2704    |
| A red Paste                                    | 2842    |
| Lapis Nephriticus                              | 2894    |
| Lapis Amiantus from Wales                      | 2913    |
| Lapis                                          |         |
| Item                                      | Value |
|-------------------------------------------|-------|
| Lapis Lazuli                              | 3054  |
| An Hone                                   | 3288  |
| Sardachates                               | 3598  |
| A Granat                                  | 3978  |
| A Golden Marcasite                         | 4589  |
| A blew Slate with shining Particles       | 3500  |
| A mineral stone, yielding 1 part in 160 Metal | 2650  |
| The Metal thence extracted                 | 8500  |
| The (reputed) Silver Ore of Wales         | 7464  |
| The Metal thence extracted                 | 11087 |
| Bismuth                                   | 9859  |
| Spelter                                   | 7065  |
| Spelter Soder                             | 8362  |
| Iron of a Key                             | 7643  |
| Steel                                     | 7852  |
| Cast Brass                                | 8100  |
| Wrought Brass                             | 8280  |
| Hammer'd Brass                            | 8349  |
| A false Guinea                            | 9075  |
| A true Guinea                             | 18888 |
| Sterling Silver                           | 10535 |
| A brass Half-Crown                        | 9468  |
| Electrum, a British Coin                  | 12071 |
| A Gold Coin of Barbary                    | 17548 |
| A Gold Medal from Morocco                 | 18420 |
| AMentz Gold Ducat                         | 18261 |
| A Gold Coin of Alexanders                 | 18893 |
| A Gold Medal of Q. Mary                   | 19100 |
| A Gold Medal of Q. Elizabeth              | 19125 |
| A Medal esteem'd to be near fine Gold     | 19636 |

II. Extracts of some Letters from Mr. John Sturdie of Lancashire concerning Iron Ore; and more particularly of the Hämatites, wrought into Iron at Milthrop-Forge in that County. Communicated by Dr. Martin Lister, S. R. S.

Townley, March 14. 1674.

SIR,

YOU will receive herewith some of the Cinder you desir'd, as also a little of Iron-stone both burnt and unburnt. They have several sorts of Iron-stone, and of