Volume 2

Reports of the commission appointed by the Admiralty, the War Office, and the civil government of Malta, for the Investigation of Mediterranean Fever / under the supervision of an Advisory Committee of the Royal Society.

Date:
1905-1907
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Reports of the commission appointed by the Admiralty, the War Office, and the civil government of Malta, for the Investigation of Mediterranean Fever / under the supervision of an Advisory Committee of the Royal Society. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    73/84 (page 71)
    Further, by plating out various fractions of a loopful of 72 to 96-hour- old agar cultivation and enumerating the colonies that subsequently developed, an approximate estimation was obtained of the number of cocci per loopful—that is to say, contained in 0*5 milligramme culti- vation. The average determined from a large series of experiments worked out to 1,250,000,000 cocci per loopful. Now as in some of the preliminary inoculations more than one slant tube culture was required to produce a fatal infection, several observations were made to determine the average number of loopfuls per cultivation. After many trials this was found to be 25 ; and all the doses in the detailed table of inoculations are calculated as loops, and so recorded—although in the first few inoculations the figures can only be regarded as approximately correct, for these doses were not measured accurately, on account of their size. Method of Inoculation. As the intercranial method of inoculation is not amongst those most commonly practised, some details of the technique I adopted may be of interest. The guinea-pig is first fully anaesthetised by means of a mixture of alcohol, chloroform, and ether, in the proportion of 1 : 2 : 6 (Ai, C2, Eo), administered on a piece of absorbent cotton-wool placed either in the corner of a folded towel, or in the bottom of a small conical glass beaker. The animal is then fastened down to the operating table, or firmly held by an assistant, and the hair of the scalp moistened with a solution of soft soap in 2-per-cent. lysol, which, with the help of hot water and cotton-wool, is worked up into a lather. The entire scalp, from the occipital protuberance to the root of the snout, is shaved, and finally washed with warm lysol solution. A median incision commencing over the occiput and running forwards for about 2 cm., is made through the skin and subcutaneous cellular tissue, and retractors, secured by the assistant, used to hold open the wound. The periosteum is next divided along the entire line of the skin incision, then raised with a blunt dissector and also secured by the retractors. A small nasal trephine (Curtis's), having a tooth-cutting circle of 6 mm. diameter,* is attached to a dental engine, and a small disc of bone removed from the left parietal bone; this trephine hole is cut well to one side of the median line to avoid injuring the superior * This instrument has been adapted for me by Messrs. Down Bros, by the addi- tion of an adjustable collar guard, secured by a screw, to prevent laceration of the dura mater or brain substance.