the Ethiopian stone, mentioned as being used to make the first incision in the corpse, might have been a piece of obsidian or basalt, but most probably was merely an ordinary sharp flint of a dark colour.

The first chemical used in embalming is the hardest nut of all to crack, and on which I have most exercised my intellectual teeth — and that is natron. Now, what is natron? [Footnote: Natrium is the old Latin term for the metal or base we now call sodium. The old names for some of its salts were: Natron Carbonicum--or Bicarbonate of Soda; Natron Vitriolatum — or Sulphate of Soda; discovered or re-discovered about 1670. Nitrum =Carbonate of soda.] Ordinary dictionaries and authors tell us, as a matter of course — carbonate of soda. In support of this theory M. Rouyer writes:

"The natron would be used just as it was got from many of the lakes of Egypt, where it is found abundantly in the form of carbonate of soda."

Pereira, in "Materia Medica," though intimating that natron is not to be confounded with nitre, says, in speaking of carbonate of soda:

"This salt was probably known to the ancients under the term of Nitron." (Nitron)

Now, as ( Nitron) is more likely, from its etymology, to be translated "nitre," we are landed into another difficulty, if by nitre we mean saltpetre, for that will, as we all know, preserve animal tissue for a certain time; however, I do not think we can translate natron as being nitre (saltpetre), for in former days many salts were included under the general term nitre; for instance, our common soda and potash, the chemical composition of which was unknown until Davy, in 1807, extracted the metals sodium and potassium from those salts. Boitard expressly states:

"Il parait que ce natrum était un alkali fixe, et pas du tout du nitre comme quelques auteurs l'ont pensé; ce qui semblerait appuyer cette opinion, c'est que lea femmes egyptiennes se servaient de natrum pour faire leur lessive, comme on as sert aujourd'hui de la soude."

In Peru the soil may be said to be impregnated with nitre, but that is nitrate of soda, and not really saltpetre (nitrate of potassium), as many people imagine who hear it called simply nitre.

Mr. Thos. W. Baker, who has most obligingly unearthed several old works for me, says:

"Now I think of it, natron is perfectly familiar to me as apparently a mixture of broken soda crystals and a brown earth which is sold in the bazaars of India, under the name of 'sootjee moogee,' for domestic purposes; and I know, from experience, that unless it is washed off paint work directly it is passed over it with a cloth all the paint comes off bare, sometimes to the wood."

Again, he says:

"In Bayley's Dictionary, circa 1730, I find the following: 'Natron; or, a Natron, from Gr. Natron (?) ( Natron), a kind of black greyish salt, taken out of a lake of stagnant water in the territory of Terrana, in Egypt."

Also see "Penny Cyclopaedia," vol. xvi., p. 105, "Natron, native sesquicarbonate of soda (see 'Sodium'):"

"The Natron Lakes, which are six in number, are situated in a valley bordering upon Lower Egypt, and are remarkable for the great quantity of salt which they produce. The crystallisations are both of muriate of soda (or common salt) and of carbonate of soda. ... The "Natron" is collected once a year, and is used both in Egypt and Syria, as also in Europe, for manufacturing glass and soap, and for bleaching linen."

Turning to "Sodium" for the sesquicarbonate, which is found native in Hungary, and also near Fezzan, in Africa:

'By the natives it is called "Trona." It is found in hard striated crystalline masses, and is not altered by exposure to the air, but is readily soluble in water. This salt appears to be formed when a solution of the carbonate of soda is heated with carbonate of ammonia, and probably also when a solution of the bicarbonate is heated. Its taste is less alkaline than that of the carbonate, into which it is converted when strongly heated by losing one-third of its carbonic acid.'

That it was one of the products of soda cannot reasonably be doubted. Biborate of soda (with which I have been experimenting lately) has certainly wonderfully preservative powers, especially in conjunction with common salt, or saltpetre; but then it has not the caustic properties of natron. May not natron have been a fixed alkali, or has the native carbonate of soda more caustic and antiseptic properties than the usual carbonate of soda of commerce, which plainly cannot be intended?

We have here a most interesting subject to solve as to the component parts of the ancient natron; my suspicion is that natron, as used by the Egyptians, was a mixture of biborate of soda, caustic soda, and muriate of soda. [Footnote: The following report appeared in the California Alta, 24th June. 1874:

"AN INTERESTING DISCOVERY. — Several weeks ago we mentioned the departure of Mr. Arthur Robottom, Birmingham, England, on a search for borax in the southern part of California. He has now returned, bringing news of an interesting and valuable discovery. Beyond the Sierra Nevada, in the Enclosed Basin of North America, about 140 miles in a north-eastward direction from Bakersfield, there is the bed of a dry lake filled over an area of fifteen miles long by six wide with saline crystals to a depth of about six or eight feet. The appearance of the surrounding country clearly indicates that water once stood sixty feet deep here over a large area, the ancient beach being distinctly traceable. The most remarkable fact about this-saline deposit is that in its middle there is a tract, five miles long and two wide, of common salt, while on the outside there is a deposit of borate of soda, three feet thick, and under this a lower stratum composed of sulphate of soda and tincal mixed together, from one to three feet thick. These minerals are all in crystals, the sulphate of soda and tincal forming a solid mass, almost like stone in its hardness. The borate of soda is of a dirty hue, but the salt, which lies above the level of the entire deposit, in some places to a depth of seven feet, is white as snow. The report of natural deposits thus situated will appear very improbable to scientific men, for there is nothing to account for the separation of the salt from the borates, or for the accumulation of salt above the level of other crystalline deposits. We have Mr. Robottom for authority, and the country is open for those who wish to examine for themselves. The place can easily be found. It is known as the Borax Fields in the Slate Range, and will be examined carefully by many competent men, since the tincal — a crude borate of soda — is a valuable mineral, and can be separated, at little expense, from the sulphate of soda."]

The next chemical agent we have to notice (which should, however, have appeared prior to natron), is palm wine, used in the first process of cleansing the intestines; this would doubtless act as an astringent, and would, of course, tend to coagulate the liquid albumen contained in the body (in a similar manner to our ordinary spirits of wine), which, if followed by a caustic alkali (such as natron may have been), to dissolve the solid albumen, fibrin and gelatine, ought certainly to have exercised a decidedly tanning influence.

Following this is oil of cedar. The present oil of cedar (ol cedrat of commerce) cannot be intended, as that is made from the citron, and being merely an essential oil can have little of the antiseptic or corrosive qualities imputed to the ancient oil of cedars. May it not have been a product distilled from the actual cedar tree (one of the coniferae) similar to our