Imágenes de páginas


6.3 13.9

I. C 47.7

H 6:2
N 13.9
ClO3 11.7


36 26.8

4:4 11. 0.4 1



5.8 13.5 19.2

1.4 12.9


I have, for simplicity, left out the phosphorus ; I do not even know if it exists in this compound.


III. 47.9



II. C 48.1

H 6:4
Ci 03 12.3


The quantity of sulphamid in fibrin and casein is different from that in albumen, but the difference is small, and therefore I pass it over here.

These bodies are the chlorites of albumen, fibrin, and casein. They produce sulphuret of silver, on being heated with potash upon silver, and thus they can be easily distinguished from the chlorite of protein containing hyposulphurous acid, which does not possess this property.

The latter may be prepared in different ways-among others, from the solutions, from which protein has been precipitated, or by passing chlorine, for a long time, through a mixture of albumen, fibrin, casein, horn, hair, whalebone, &c., and water. The product always contains a certain quantity of hyposulphurous acid arising from the decomposition of sulphamid and water 2 (S NH” + H 0). The action of the chlorine upon this produces ammonia, which unites with hydrochloric acid,—and hyposulphurous acid, which, along with chlorous acid, is taken up by the organic compound.

In my former letter to you, I reduced the composition of protein with hyposulphurous acid, as it is obtained from albumen, to a group free from this mixture. I then brought into account 1.4 per cent. of sulphur, as was found by Fleitmann. The normal quantity obtained by fusion with soda, and subsequent addition of saltpetre, is 1.6 per cent., and this I believe to be the true proportion of sulphur in albumen. The compound consists of —

[blocks in formation]

This combination is present in the substance obtained by the long continued action of chlorine upon one of the above named substances. Only when prepared from albumen, it yields exactly the above proportion of hyposulphurous acid ; but when obtained from the solution of fibrin, from which protein has been precipitated, it only contains 0:6 per cent. of sulphurous acid, and yet it consists of C36 H” N01, minus 1 or 2 equivalents of water, according as 1 or 2 equivalents of chlorous acid have been taken up into the combination,

I here subjoin the composition of chlorites of protein containing hyposulphurous acid, as they are obtained from horse-hair, humanhair, whalebone, and trioxide of protein, (Scheck. Onderz. deel i., p. 265 ; deel ii., p. 403), according to my former results :

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small]

Chloride of protein prepared from the trioxide (former results) :

[blocks in formation]

You will perceive, that these old results agree even better with the formula C36 H25 N° 010, than with the former I gave for protein. The determination of chlorine is accompanied by several difficulties ; and in some of my former results the quantity found was too small.

I have obtained the following results by analysing compounds which shewed no action upon silver when heated upon it with potash. I have now dried them under the air-pump, over sulphuric acid, by which means, if well prepared, they retain 2 equivalents of chlorous acid. They are as follows:

From albumen,

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors]

When this compound, which is a bichlorite of protein, is dried at 212° F., it contains only 12:17 per cent. of chlorous acid.

The same body may be obtained from the solution of fibrin, from which protein has been precipitated, but this contains only 0:6 per cent. of hyposulphurous acid.

If through the solution of albumen, from which protein has been separated, a current of chlorine is passed, a combination is always obtained of C36 H25 N+ 010 with chlorous and hyposulphurous acids, but in variable proportions. That of the latter acid varies, which apparently indicates that the sulphur is not inseparable from C36 H N O10, and is no essential ingredient of protein. But the quantity of chlorous acid also varies, and the cause of this is, that, if the current of chlorine is continued for a sufficient length of time, we obtain mixtures of protein with one or two equivalents of chlorous acid.

I here give you the result of the analysis of these bodies, and this I do for two reasons :

1st, Because these very mixtures afford a proof that the combination contains chlorous acid, and not chlorine.

2d, Because they shew, that the sulphur they contain, is an accidental and not an essential ingredient.

[blocks in formation]

Here the proportion of sulphur is from 0.8 to 1:0 per cent., being, in the first instance, lessened to half the quantity contained in albumen.

Any one who can explain these results in another way, will do a service to science by making it known. I consider these bodies as

mixtures of neutral and acid combinations of chlorous acid, with C36 H” N+ 010, and a variable quantity of hyposulphurous acid.

All these chlorites dried over sulphuric acid at the ordinary temperature, appear white and pure. They have all the same properties, and tend to confirm the doctrine of protein.

As we must distinguish between chlorite of protein with hyposulphurous acid, and chlorite of albumen, fibrin, &c., we must do so also with their other combinations.

Thus, we must call the compound, which I have formerly analysed, * tannate of albumen. It consists ofm



C 54.2
H 5.6
N 10.5



Calculated. 53.9

5.6 10.2 29.2 1.1

=(C36 H N+ 10 +(0:4 SN H-) + H 0)+(C18 H” O' + 2 H 0); that is, albumen with tannic acid, which has exchanged one equivalent of water for one equivalent of albumen. You see, that this formula agrees also better than the former with my old results.

The same applies to sulphuric acid with albumen, and sulphuric acid with protein.

When protein containing hyposulphurous acid is dissolved in strong sulphuric acid, the former is expelled and replaced by the latter, in a quantity amounting to 5 per cent.

In my following communications to you, I hope to treat of these and other combinations.

Believe me,

Yours faithfully,

(Signed) G. T. MULDER. To Professor JOHNSTON.

Important Information regarding the Cultivation of Tea in the

Valley of the Dhoon, India.

The last Calcutta Gazette contains a very important dispatch from the Court of Directors, relative to the capabilities of the Valley of the Dhoon, and the adjacent districts, for the production of tea. Several valuable reports have recently appeared in the local journals of the success which has attended the efforts of Dr William Jameson (nephew of Pro

* Bulletin, 1839, p. 18.

fessor Jameson), Superintendant of the Botanic Gardens in | the north-west Provinces of India, to introduce the cultiva

tion of this plant in the north-west, and the public have, therefore, been in a measure prepared for the very gratifying intelligence now communicated to the community. But the report of the tea-brokers in England on the quality of the article submitted to their inspection, exceeds our most sanguine expectations. They have pronounced it equal to China tea of a superior class, possessing the flavour of the orange pekoe, but more than the usual strength of that tea, in other respects resembling that imported as Ning Yong. One of the gentlemen whose opinion has been obtained, declares, “ that the tea shrub in Kemaoon is not only identical with the China plant, and as capable of being made into as fine a description of tea, but also that the soil and climate in Kemaoon are as suited to the favourable growth of the shrub as the finest of the China localities.” The tea appears to be as much prized in the district in which it has been raised as it is in England, One hundred and seventy-three seers of it were recently sold at Almorah, and produced from four to five rupees the seer, which was equal to the price of the best tea sold in Calcutta, at the great tea depot of D). Wilson & Co. The price for which it can be raised, according to Dr Jameson's calculation, is so low as to afford the greatest encouragement to the application of capital. He estimates, that if cultivated on a sufficiently large scale, the prime cost in Calcutta, including every expense, would be little more than eight annas a seer, or oneeighth of the present price. Supposing, however, the cost of cultivation, manufacture, and transport, to be double this estimate, a sufficient margin of profit would still be left to gratify the most sanguine speculator. The capacity of the provinces of Kemaoon and Gurhwall for the enlarged production of the article, does not, moreover, appear to be limited to particular localities. According to the latest report which has been furnished to the Court, 176 acres were under cultivation, containing not fewer than 322,579 plants. The crop is thriving in different places over four degrees of latitude and three degrees of longitude, and 100,000 acres are now available in the Dhoon alone for the purposes of tea cultiva


« AnteriorContinuar »