CHEMISTRY. 



CHESEBRO, CAROLINE. 109 



In yellow. In a quarter of a minute, 22 bubbles. 



In orauare next yellow, 19 



In middle orange. 



In orange uezt red, 14 



In red next orange. 



In red farther off, 4 



In " 8 " 



In .. .. " a 



In extreme red, 1 " 



Black to yellow, Si 

 In yellow, In a quarter of a minute, 35 babbles. 



In middle of green, 9 " 



In middle of bine, 6 " 



In middle of indigo. 4 " 



In middle of violet, " 8 



Back to yellow, 84 



(It may be observed that, where the process be- 

 came very slow, counting was continued for half a 

 minute to one minute, and then a reduction made.) 



Dr. Pfeiffer next experimented by placing a chlo- 

 rophyll notation in the path of the rays, and bringing 

 the plant to the band between B and C, which, with 

 a breadth of 10 millimetres, almost entirely covered 

 it. The number of bubbles given off here was com- 

 pared with that in the bright yellow. Reckoning the 

 latter as 100, the average Tor the other was 29.1. 



Thus, no connection is indicated between absorp- 

 tion of the liifht-rays in a chlorophyll solution, and 

 the "assimilation-value" of these absorbed rays. 



On the other hand, the little-absorbed yellow rays 

 appeared most active in decomposing CO 3 , and what 

 appeared the brightest part of the yellow gave most 

 bubbles ; so that, on moving the plant even a very 

 little on either side, and without leavinz the yellow, 

 the number of bubbles diminished. For example, 

 the following bubble-number*, were got in half a 

 minute's exposure: 



In brightest yellow 42 bubbles. 



A little toward preen. 40 



Back to flrat position 48 " 



In brightest yellow 43 bubbles. 



A little toward orange 40 " 



Back to 4rt position 42 



From a large collation of instances are obtained 

 the following average values for the several spectral 

 rays, reckoning the number of bubbles in the yel- 

 low at 100: 



Red K.4 



Orange 63.0 



Yellow 100.0 



Green 87.4 



Bine Sil 



Indigo. 13.S 



Violet 7. 1 



The curve formed in accordance with these num- 

 bers agrees very nearly with the curve obtained by 

 Vierordot in his measurement of brightness in the 

 olr spectrum. From the culmination-point in yel- 

 low, to the middle of orange and green, they are al- 

 most alike ; thereafter they diverge silently. 



Now, this curve obtained from bubble-numbers 

 does not truly represent the assimilation - curve. 

 The numbers (as Dr. Pfeiffer had pointed out in a 

 previous paper) were too high, and the more so the 

 less carbonic acid was decomposed in given circum- 

 stances. The relation between the values for the 

 gas-bubbles, and the quantity of COj decomposed, 

 is, on account of individual peculiarities and other 

 causes, not constant, and must bo determined em- 

 ptricallv. If. however, the proper reduction be 

 made, Dr. Pfeiffer thinks the curve then obtained 

 will have a still closer resemblance to the bright- 

 ness-curve. 



Still, the agreement of the gas-bubbles carve with 

 the brightness-curve is so close as to warrant Dra- 

 per's conclusion, as to decomposition of CO, in 

 plants, that the decomposing force of the various 

 rays corresponds in general to their apparent bright- 

 ness in the spectrum. 



Suint. It has been ascertained that sheep 

 derive from the soil upon which they pasture 



a considerable amount of potash, which, after 

 it has circulated in the blood, is excreted by 

 the skin with the sweat, and remains, gener- 

 ally in connection with this, attached to the 

 wool. Chevreuil discovered, some time ago, 

 that this peculiar mixture, known by the 

 French as tuint, constitutes not less than one- 

 third the weight of the raw merino fleece, 

 from which it is easily removed by immersion 

 in cold water. In ordinary wools the suint is 

 less, the amount being about fifteen per cent. 

 of the raw fleece. Formerly it was consid- 

 ered as a kind of soap, mainly for the reason 

 that the wool, besides this, sometimes con- 

 tained about eight per cent., or a not incon- 

 siderable quantity, of fat. This fat, however, 

 is usually combined with earthy matters, most- 

 ly with lime, and consequently forms a soap 

 which is very insoluble. The soluble suint is 

 a neutral salt arising from the combination of 

 potash with a peculiar animal acid, of which 

 little more is known than that it contains salt- 

 petre. Attention has lately been directed to 

 suint, in order to obtain as much as possible 

 of the potash eliminated from the animal, and 

 a special industry has been established in vari- 

 ous portions of the great French wool district, 

 such as Reims, Elboeuf, etc. A company 

 purchases from the wool-raiser the solution of 

 the suint obtained by rinsing the wool in cold 

 water, the price paid for it being higher in 

 proportion as it is more concentrated. As a 

 general rule, it is maintained that a fleece 

 weighing nine pounds contains about twenty 

 ounces of saint, which should contain about 

 one-third part, or six to seven ounces, of pot- 

 ash, although not more than five and a half 

 ounces are perhaps directly available. In the 

 wool-manufactories of the towns referred to, 

 there are nearly 60,000,000 pounds of wool 

 washed annually, the yield of about 6,750,000 

 sheep. This quantity should contain over 

 8,000,000 pounds of pure potash. Thus the wa- 

 ter in which the wool is washed, and which 

 has heretofore been thrown away, is made to 

 yield a product adding appreciably to the 

 value of the wool itself, and more than cover- 

 ing the cost of the treatment. It is, of 

 course, not an easy matter to utilize this solu- 

 tion of suint on a small scale, but wherever 

 the work is carried on wholesale, as it is in 

 connection with all great manufacturing estab- 

 lishments, it will undoubtedly become a regu- 

 lar part of the process of manufacture. 



CIIESEBRO, CAROLINE, an American au- 

 thoress and teacher, horn in Canandaigna, N. 

 T., about 1828; died in Piermont, N. J., Feb- 

 ruary 16, 1873. Miss Chesebro's education 

 was obtained mostly in her native village, 

 which has for many years borne a high reputa- 

 tion for the excellence of its female seminaries. 

 She commenced writing for the magazines 

 about 1848, contributing at first to Graham's 

 and ffolden't Dollar Magazine. In 1851, a vol- 

 ume of her stories and sketches was collected 

 and published with the title of "Dream-Land 



