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On the value of different kinds of soap
On the ITalue of 2Oifferent Kinds of Soap.
109
adopting for the standard the inch already recognised and in general use, so that the introduction of the decimal subdivision involved no change of measure. The improvements that had taken place in the construction of machines, and the remarkable truth and accuracy with which work was now executed, rendered it essential for the progress of mechanical science that ~J ~ t h of an inch should be readily appreciated in the workshops by ordinary workmen. The Whitworth and Enfield rifles were bored out to ~ ] ~ t h of an inch, and workmen soon became accustomed to work with extreme accuracy and truth. With the decimal system much greater accuracy was obtained than with ordinary fractions, by employing the sense of touch on Mr. Whitworth's plan of end or contact measurement, by which smaller dimensions than z~'0oth of an inch were readily appreciated ; and, in practice, it was required to have the means of expressing dimensions down ~o ~ ' ~ t h of an inch, as illustrated by the results given in the paper just read. Different descriptions of wheels required to be bored out with slightly different allowances in the diameters ; ~t solid cast iron wheel requiring to be bored out larger than a wheel with a light boss and spokes ; and this difference could be readily mea,~urcd and worked to by the decimal system with the use of g~mgcs in the manner that had been dcscribed.--/)rov. ;?leeh. .Er~y. ~S'vc.
On the Value of 1)idferent Kinds of Soap,
:By R. GRAEC,Ett.
Fvoal the Lolad. Chemical News, No. 68.
ComplMnts of consumers in regard to the value, or rather efficacy, of samples of soap, which to the best of the manufacturer's knowledge have been well prepared, are not uncommon. ]t is very probable that the usual explanation which is offered, ~'henever ~ soap fails to fulfil the expectations of its consumer, viz : that it contains too much water, may be in many cases correct. Admitting this, and various other contingencies, which are of importance in deciding upon the value of a soap, there appears to be another obvious reason why different soaps containing equal amounts of water may still possess different degrees of efficacy. It is evident from the difti~rent equivalent weights of the various f,~tty acids, that the amounts of caustic alkali taken up by them in the formation of soap must be of unlike magnitude. If it be true, that the detergent power of soap is entirely dependent upon the ~rmount of alkali which it contains, of course it follows tl~at those soaps which contain the largest proportion of a l k a l i , ~ o r in other words, those containing a fatty acid, the equivalent weight of which is small,--must be the most efficacious. Since the difference between the equiwlents of the common fatty acids is not large, these considerations are, perhaps, of little or no importance in so far as concerns the consumption of soap in househohl economy~the total amount used in ~ single family being but small. In ~ manufacturing establishment, however, where fifty or a hundred Vote. X L I I , ~ T H I a D Sm~J~s.-- .No. 2.--At:G~:er, 1861.
10
~feJ~anics, ]Physics, and Chemistry.
110
thousand pounds of soap may be used in the course of a year, differences which cannot be deemed insignificant must exhibit themselves. :For example, the equivalent weights of several soaps (regarded as anhydrous), in common use, are as follows : - O l e i c a c i d ( r e d oil) s o a p , P a l m oil " Tallow " C o c o a - n u t oil "
~--.,'3800'95 ----- 3 5 8 8 " 8 5 ~ 3300.95 ~ 3065.45
•
Calculating from these weights how much of each of the other soaps would be required to replace 1000 pounds of tallow soap, the following quantities will be found : - 1151 lbs. o f olelc a c i d s o a p , 1087 " p a l m oil " 928 " c o c o a - n u t oil "
i.e., i.e., i.e.,
15.1 p e r c e n t . m o r e t h a n t a l [ o w s o a p . 8"7 " " 7.2 " less "
Differences like these must certainly be of importance in practice; and could, doubtless, be detected by direct experiment, if any one ~ould undertake a comparison of the various kinds of soap--a research which would not be easy, however.--Boettger's Polytechnisehes
2Yotizblatt. Artesian Well. The Cosmos announces the final success of the artesian well which has been sunk at Passy near Paris for the purpose of furnishing the water for the artificial rivulets of the Bois de Bologne. The bed of water was met at a depth of 577 metres (1893 feet) on Saturday at 4 o'clock, A. M., and on Sunday it had risen to from 6 to 9 feet below the surface. The slowness of its rise is caused by the tube being choked with sand, which, however, is supposed not to come from any caving in of the sides or bottom of the bore.
On Boilers and Boiler ]Plates. By Mr. RAMSELL. F r o m Newton's London Journal~ June, 1861.
The author remarked, primarily, that twenty years experience in the construction of steam boilers had given him some practical knowledge of his subject, and that, therefore, he had little diffidence in speaking uppn it. He had long ago become convinced of the necessity of adopting a different principle to that usually acted upon in the manufacture of boilers ; and a very important poifit was to do away with "stays," as used for strengthening them. More especially, he referred to marine boilers, and instanced, in the following order, three principal evils attending the employment of stays : 1st, the obstruction they offered to the effectually cleaning of the boilers; 2d, the increased amount of incrustation induced by them; and, 3d, the water and steam space they occupied. The fracture of the steel boilers of the John Penn, S. V., which came especially under his notice last year, prompted him to give more consideration to the subject. In those
109
adopting for the standard the inch already recognised and in general use, so that the introduction of the decimal subdivision involved no change of measure. The improvements that had taken place in the construction of machines, and the remarkable truth and accuracy with which work was now executed, rendered it essential for the progress of mechanical science that ~J ~ t h of an inch should be readily appreciated in the workshops by ordinary workmen. The Whitworth and Enfield rifles were bored out to ~ ] ~ t h of an inch, and workmen soon became accustomed to work with extreme accuracy and truth. With the decimal system much greater accuracy was obtained than with ordinary fractions, by employing the sense of touch on Mr. Whitworth's plan of end or contact measurement, by which smaller dimensions than z~'0oth of an inch were readily appreciated ; and, in practice, it was required to have the means of expressing dimensions down ~o ~ ' ~ t h of an inch, as illustrated by the results given in the paper just read. Different descriptions of wheels required to be bored out with slightly different allowances in the diameters ; ~t solid cast iron wheel requiring to be bored out larger than a wheel with a light boss and spokes ; and this difference could be readily mea,~urcd and worked to by the decimal system with the use of g~mgcs in the manner that had been dcscribed.--/)rov. ;?leeh. .Er~y. ~S'vc.
On the Value of 1)idferent Kinds of Soap,
:By R. GRAEC,Ett.
Fvoal the Lolad. Chemical News, No. 68.
ComplMnts of consumers in regard to the value, or rather efficacy, of samples of soap, which to the best of the manufacturer's knowledge have been well prepared, are not uncommon. ]t is very probable that the usual explanation which is offered, ~'henever ~ soap fails to fulfil the expectations of its consumer, viz : that it contains too much water, may be in many cases correct. Admitting this, and various other contingencies, which are of importance in deciding upon the value of a soap, there appears to be another obvious reason why different soaps containing equal amounts of water may still possess different degrees of efficacy. It is evident from the difti~rent equivalent weights of the various f,~tty acids, that the amounts of caustic alkali taken up by them in the formation of soap must be of unlike magnitude. If it be true, that the detergent power of soap is entirely dependent upon the ~rmount of alkali which it contains, of course it follows tl~at those soaps which contain the largest proportion of a l k a l i , ~ o r in other words, those containing a fatty acid, the equivalent weight of which is small,--must be the most efficacious. Since the difference between the equiwlents of the common fatty acids is not large, these considerations are, perhaps, of little or no importance in so far as concerns the consumption of soap in househohl economy~the total amount used in ~ single family being but small. In ~ manufacturing establishment, however, where fifty or a hundred Vote. X L I I , ~ T H I a D Sm~J~s.-- .No. 2.--At:G~:er, 1861.
10
~feJ~anics, ]Physics, and Chemistry.
110
thousand pounds of soap may be used in the course of a year, differences which cannot be deemed insignificant must exhibit themselves. :For example, the equivalent weights of several soaps (regarded as anhydrous), in common use, are as follows : - O l e i c a c i d ( r e d oil) s o a p , P a l m oil " Tallow " C o c o a - n u t oil "
~--.,'3800'95 ----- 3 5 8 8 " 8 5 ~ 3300.95 ~ 3065.45
•
Calculating from these weights how much of each of the other soaps would be required to replace 1000 pounds of tallow soap, the following quantities will be found : - 1151 lbs. o f olelc a c i d s o a p , 1087 " p a l m oil " 928 " c o c o a - n u t oil "
i.e., i.e., i.e.,
15.1 p e r c e n t . m o r e t h a n t a l [ o w s o a p . 8"7 " " 7.2 " less "
Differences like these must certainly be of importance in practice; and could, doubtless, be detected by direct experiment, if any one ~ould undertake a comparison of the various kinds of soap--a research which would not be easy, however.--Boettger's Polytechnisehes
2Yotizblatt. Artesian Well. The Cosmos announces the final success of the artesian well which has been sunk at Passy near Paris for the purpose of furnishing the water for the artificial rivulets of the Bois de Bologne. The bed of water was met at a depth of 577 metres (1893 feet) on Saturday at 4 o'clock, A. M., and on Sunday it had risen to from 6 to 9 feet below the surface. The slowness of its rise is caused by the tube being choked with sand, which, however, is supposed not to come from any caving in of the sides or bottom of the bore.
On Boilers and Boiler ]Plates. By Mr. RAMSELL. F r o m Newton's London Journal~ June, 1861.
The author remarked, primarily, that twenty years experience in the construction of steam boilers had given him some practical knowledge of his subject, and that, therefore, he had little diffidence in speaking uppn it. He had long ago become convinced of the necessity of adopting a different principle to that usually acted upon in the manufacture of boilers ; and a very important poifit was to do away with "stays," as used for strengthening them. More especially, he referred to marine boilers, and instanced, in the following order, three principal evils attending the employment of stays : 1st, the obstruction they offered to the effectually cleaning of the boilers; 2d, the increased amount of incrustation induced by them; and, 3d, the water and steam space they occupied. The fracture of the steel boilers of the John Penn, S. V., which came especially under his notice last year, prompted him to give more consideration to the subject. In those